Optical data storage and optical recording and reading

 

(57) Abstract:

The invention relates to optical data storage devices. Memory data memory formed of a transparent homogeneous base material and a number of optically active structures on one side of the memory data. Optically active structures are diffractive optical elements. These elements can focus a beam of light incident on one or more points memory data memory data, and/or focusing the redirected beam of light or the emitted light radiation from this point or these points on a point outside the optical data carrier. During the read/write data in the data carrier diffractive optical elements used to focus the beam of the read/write. The technical result of the invention consists in the formation of the structure of the data storing or reading data stored in a data storage structure. The invention achieves the parallel read/write data, possibly in several parallel layers of storage in an optical storage device. Optical data carrier provides true surround the storage data and the corresponding systematic storage of data, contains the memory location of data generated substantially transparent homogeneous base material and a number of optically active structures in the form of diffractive optical elements adjacent to one side of the field data memory, in which each of the diffractive optical element is adapted to focus a beam of light incident on one or more points to the data memory, each of which corresponds uniquely addressable cell of the data storage structures, which must be formed or is formed by the data storage structure in the area of data memory, and/or focusing the redirected beam of light or the emitted light radiation from this point or these points on a point outside the optical data carrier. The invention also relates to a method of recording data in accordance with the restrictive part of the PP. 13 and 14 of the claims, methods of reading data in accordance with the restrictive part of the PP. 17 and 18 claims, respectively. In addition, the invention also relates to a method of parallel recording data in accordance with the restrictive part p. 20 of the claims and how the parallel read data in sootvetstvenno in optical data storage devices in the form of rotating discs, rectangular cards or sheets, or tapes in the form of strips or coils.

The present invention is particularly suitable for use in connection with a data carrier and a method of creating a data storage structures such data carriers, which are described in published international patent application WO 96/37888, entitled "Optical data storage", which is owned by the present applicant and which will continue to be used as reference.

In the optical storage of digital data, in accordance with the prior art, sharply focused laser beam systematically scans over the surface of the data carrier, usually a rotating disk, and the contents data are displayed by recording the changes in reflected from the disk light when the laser beam passes microscopic cavities or stains that have been encoded on the media. High data density can be achieved when depression or spots are small and are close to each other. Depression or spots, which form a data storage structures may be either molded or pressed during manufacture of the disk, or can be used with a scanning laser beam to encode the data in the disk Posner, in the form of depressions.

This method of optical storage of data and access to it has several disadvantages. Requires high-precision opto-mechanical system to position the laser beam precisely on the track containing the data, and the data is read sequentially. This imposes limitations due to the mechanical system, and also reduces the speed of random access. The latter problem is particularly serious in many applications, and is currently undergoing extensive research aimed at the development of designs is more light optical heads, which make possible more rapid mechanical positioning. Methods based on the use of mechanical systems, however, are not suitable for achieving very high access speeds, and therefore, significant resources have been invested in research aimed at the development of the addressing schemes of the light rays based on acousto-optic or electro-optic effects. Because at present, such schemes can be designed as a compact and preferably cheap physical blocks, the integrated optical structures are of particular interest to researchers.

Even if the above, the C-sequential access to the stored information and the applied method of tracking the data transfer rate will remain a serious problem. To resolve it, a study was conducted on the basis of multi-track solution, where data is transmitted parallel to the optical heads that write and read a number of adjacent tracks. For a single optical head that is controlled by a servomechanism, only a few neighboring tracks can be covered in such a way as to achieve a higher speed requires several independent witness heads. The degree of concurrency of read and write, achieved by such means, is strictly limited to physical and price framework.

An example of an optical storage device, which eliminates the problems associated with addressing modes, based on the use of mechanical systems, disclosed in published international patent application WO 93/13529. The data stored in the optical layer 19, is capable of selectively changing light, for example, by changing the transmittance, reflectance, polarization and/or phase. The data layer 19 is covered controllable light sources 15, and the matrix of transmitting image consistent lighting different areas or data pages in the data layer respectively different configuration data are displayed corresponding microlenses 21 in the standard matrix of light sensors 27, thus making it possible to sample a large number of data pages electro-optical multiplexing. In a preferred variant embodiment of the microlenses 21 can be replaced with a diffractive optical structures 402, 406, although it should be acknowledged that if you are not monochromatic or not narrowband light sources, the diffractive optical structures cause unwanted aberration or distortion in the image data due to the different wavelengths of the source. Moreover, in this optical storage device also structurally divided optics read and write, which leads to rather complicated optical setup and the need for the introduction of beam splitter 31 in the housing 11 of the storage device.

An example of a storage device suitable for optical storage device may be a data storage device, disclosed in U.S. patent 5436871 (Russell), which is a continuation of the main international application WO 93/13529 and discloses a compact optical storage device in which data are stored on the card 104 with an integral matrix of microlenses 210 in the optical data layer 190 that can selectively alter the light by changing the coefficient, however, also made with data carrier capable of emitting fluorescent light upon excitation with a suitable light source, as disclosed in the above-mentioned published international patent application WO 96/37888, or contain chromophore composite connection, as disclosed in published international patent application WO 96/21228 reporting use of bacteriorhodopsin as connection chromophore.

The present invention is to overcome the aforementioned disadvantages associated with the technology of the prior art for optical storage of data, as well as disadvantages arising from a number of previously proposed solutions. The next task is to allow parallel access to large blocks of data in the data carrier and replace mechanical movement is entirely or partially, using addressing and logical operations based on electronics.

A special task of the present invention is to achieve a simple recording and reading optical data stored in large quantities, that is, from several hundreds to several thousands of parallel channels, and fast random access to data in nectariniidae the possibility of creating cheap media data with a high data density. Another object of the invention is the preferred use of non-coherent photoslittle, such as light emitting diodes (LED), in some applications, when the laser source is not needed. Another object of the invention is the provision of a possibility to agree on any format, whatever the medium, be it a disk, card or tape, in addition to making use of a very compact optical technical means for read/write.

The above-mentioned tasks in accordance with the invention are achieved as optical data storage device, wherein the generated diffractive optical elements with controlled speed change phase, characterized in that the memory data is formed between the transparent surface layer and the transparent substrate, the diffractive optical elements can be formed on the surface layer can be embedded in the surface layer or may be formed as a single unit with the surface layer, and between the surface layer and the memory data can be formed in the opaque layer, is able to break down the absorption of energy of radiation, and a method of recording data, otlichayushiesya the laser beam on the diffraction optical element on the optical data carrier, focusing thus mentioned laser beam mentioned diffractive optical element at a particular point in the area of data memory, whereby the energy released from the above-mentioned laser beam in the focal point in a known manner, produces a physical or chemical change in the material in a clean area of the data memory at this point, and thus creating a storage structure of the data, which is assigned to a data item whose value corresponds to the degree of physical or chemical changes in the material in said data structure; and referred to the rate of change determined by the modulation mentioned laser beam in accordance with a given modulation procedure; another method of recording data according to the invention differs in that form of diffractive optical elements with controlled speed change phase, direct the laser beam on the diffraction optical element on the optical data carrier, adjust the wavelength mentioned laser beam so that said laser beam focus mentioned diffractive optical element at a particular point in the area of data memory, whereby the energy wescoe change in the material in a clean area of the data memory at this point, thus creating a storage structure of the data, which is assigned to a data item whose value corresponds to the degree of physical or chemical changes in the material in said data structure; and referred to the rate of change determined by the modulation mentioned laser beam in accordance with a given modulation procedure; the method of reading data according to the invention differs in that form of diffractive optical elements with controlled speed change phase, direct the laser beam on the diffraction optical element on the optical data carrier, focusing thus the laser beam on a specific data storage structure in the area of data memory, whereby the energy allocated from the mentioned laser beam in the focal point in a known manner, produces optically detected response of said data storage structures such that said detected response corresponds to the value of the data item stored in the data storage structure, and the above-mentioned optically detected response focus mentioned diffractive optical element to an optical detector mounted outside the eat, what form of diffractive optical elements with controlled speed change phase, direct the laser beam on the diffraction optical element on the optical data carrier, adjust the wavelength mentioned laser beam so that said laser beam is focused on a specific data storage structure in the area of data memory, whereby the energy released from the above-mentioned laser beam in the focal point in a known manner, produces optically detected response from the mentioned data storage, so that the detected response corresponds to the value of the data item stored in said data structure, and the above-mentioned optically detected response focus through the mentioned diffractive optical element to an optical detector mounted outside the mentioned optical data carrier; and how the parallel write data according to the invention differs in that form of diffractive optical elements with controlled speed change phase, send two or more laser beam emitted by the laser device, which contains two or more separately generated by laser element, through the protected area the data set the wavelength of each laser beam so that said laser beam is focused mentioned diffractive optical element on the same plane, and the said plane corresponds to a specific layer in the storage area of the data memory, whereby the energy of each laser beam in the focal point of the well-known manner, produces a physical or chemical change in the material in a pure layer of memory data in each focal point in said plane, thereby creating in said plane, a number of data storage structures, corresponding to a series of laser beams, and assigning each data structure element data, the value of which corresponds to the degree of physical or chemical changes in the above data structure, and referred to the degree of change is determined by the modulation of the respective laser beam in accordance with a given modulation procedure; and the way of parallel read data according to the invention differs in that form of diffractive optical elements with controlled speed change phase, send two or more light beams of the lighting Pribory wavelengths, moreover, the above-mentioned wavelengths of the light rays either fixed or rebuilt using an optical device, one or more diffractive optical elements on the drive data, focusing, therefore the above mentioned light rays on certain data storage structures in the area of data memory, whereby the energy of each laser beam in the respective focal point in a known manner, produces optically detected responses from the mentioned data storage structures, focusing mentioned optically detected responses through the following optical device located on the opposite side of said media data on the optical detector elements in the optical detector device, moreover, the detected optical responses correspond to the data values assigned mentioned respective data storage structures.

In a preferred variant embodiment of the optical data storage device in accordance with the invention, the diffraction optical elements (DOE) are lens - zone plate.

In another preferred variant embodiment of the optical data storage the data storage surface of the said tape, disk or card. In another preferred variant embodiment of the optical data storage area of the data memory contains one or more layers that form one or more separate planes of storage, and this storage layer contains molecules of a fluorescent dye embedded in the base material, which forms the storage layer, and the dye molecules in each layer of storage have different spectral characteristics corresponding to the wavelength of the light beam, focused on the storage layer diffractive optical element.

The invention is illustrated by description of specific variants of its realization taking into account the principle of diffractive optical elements and with reference to the accompanying drawings, in which

Fig. 1 illustrates the optically active structures in the form of a matrix of diffractive optical elements,

Fig. 2A, b illustrate the principle of the diffraction optical element or lens - zone plate according to the present invention,

Fig. 3A illustrates a profile zones in the diffractive optical element according to Fig. 2B,

Fig. 3b, C, d illustrate various methods for approximation or quantization F. the action bars,

Fig. 5 illustrates how the incident plane wave is focused diffractive optical element on a substrate,

Fig. 6 depicts a view in section of the optical data storage device according to the present invention,

Fig. 7 is a schematic illustration of a method of parallel write data according to the present invention,

Fig. 8 is a schematic illustration of a method of parallel read data according to the present invention,

Fig. 9a, b is a schematic illustration of the principle of focusing the laser beams on the same plane according to the present invention,

Fig. 10 is a schematic illustration of a method of concurrent access by multiple layers of storage in the data storage device according to the present invention.

A fundamental characteristic of the present invention is the use of optically active structures in the form of diffractive optical elements in the data carrier, and diffractive optical elements are as many microscopic lenses. The actual media data in accordance with the present invention, therefore, becomes in effect an integral part of optical systems, which shape and direct the light, use the basic optical elements were formed with controlled speed change phase. Thus, a number of limitations encountered in conventional optical data storage methods, is eliminated, and opens the possibility of achieving high-speed recording/reading using practical and inexpensive hardware.

Diffractive optics based on diffraction in contrast to the refraction or reflection of light. In many cases, diffractive optical elements can take the place of conventional refractive optics type lenses or prisms, thus providing a substantial reduction in cost or decrease in size. In some cases, diffractive optics can provide higher performance than refractive elements, such as aromatization, or even to provide functionality that is not accessible by usual optical elements based on the refraction or reflection.

Fig. 1 illustrates a matrix of diffractive optical elements. Each diffractive optical element consists of a carefully designed topographic structures that can be produced and reproduced through a broad range of processes, such as molding, stamping, dry or wet etching.

In dlinnyh in accordance with the invention, in order to achieve the desired storage capacity. Data storage capacity will depend on the maximum density that can be obtained through the non-overlapping focus areas or focal spots on the substrate media data behind the diffractive optical element. In particular, the description will focus on the use of lenses, zone plates as a preferred variant embodiment of the diffractive optical element with a controlled speed change phase.

The principle design of diffractive optical element or lens - zone plate, is illustrated in Fig. 2. If for simplicity we assume that the plane wave with the wave front parallel to the flat surface of the lens illustrated in Fig. 2A, falls from below, only the shaded area in Fig. 1A will affect the transmitted wave front, not counting the phase factor of 2n, where n is an integer.

Therefore, the lens illustrated in Fig. 2B, will create the same last wave front, as the lens of Fig. 2A, except the fact that there is an abrupt change in the phase 2 between two different zones in the lens of Fig. 2B. Lens, such as Alcaide from the Fresnel lens, that last is a random jump of phase from one area to another because of errors in the production process, so the result field of the waves, which arise from different areas do not provide structural interference in the focal region. Therefore, the diffraction-limited resolution Fresnel lens is determined by the width of the zone, while the resolution of the lens - zone plate is determined by the diameter of the lens.

The actual profile of one of the zones of Fig. 2B is illustrated in Fig. 3A. In practice, however, it may be easier to use the marked zone profiles, as illustrated in Fig. 3b and 3C. The number of stages in the marked profile is described as the number of quantization levels for the phase function. Obviously, when the number of quantization levels becomes infinitely large, then there can be obtained a continuous profile as such, as in Fig. G principle of the design of the lens - zone plate, which will provide optimum image point on the axis, is that the optical path length from a point object to a point image through each zone in the lens must be the same as the length of a direct optical path between the object and image point, reillustrated the top view of Fig. 4A and views in the context of Fig. 4B, respectively. It is seen that the lens - zone plate consists of a series of concentric annular grooves, in which each ring is assigned a particular value of phase and amplitude. Moreover, it is well known that lenses - zone plate are the tricks of a higher order, so the result is only part of the incident energy ends desired image. It is also known that the efficiency of the lens - zone plates can be increased by increasing the number of quantization levels for the phase function. It was shown that it is possible to obtain the intensity levels 33, 57, and 67% in the main lobe betaversion image for 2, 3 and 4 quantization levels, respectively. Recently, however, have developed a new coding method, called the method RSIDO that, say, gives the measured diffraction efficiency of 90%. Another drawback of the lens - zone plate is that it has a large chromatic aberration. However, as long as the lighting is relatively monochromatic, a moderate change in the wavelength of the light relative to the wavelength used to build lenses - zone plate, will not lead to a significant deterioration in the quality of Izzat, placing the lens, zone plate or a diffraction optical element on a spherical surface.

Move the beam in the lens - a zone plate or a diffraction optical element can be found, if we consider them as a diffraction grating with different lattice period and constructing geometric rays on the basis of the equation of the lattice. Schematically shown in Fig. 4A, b lens, zone plate can be considered as shown in Fig. 4A, like a circular diffraction grating with a period, which is reduced to the edge of the lens. In the lens - zone plate shown in Fig. 4B, the field associated with the incident geometric beam, in this case a flat wave. The direction of geometric past the beam corresponding to the first order of diffraction is given by the equation lattice

< / BR>
where is the wavelength, d is the local value of the lattice period, aiandt- the angles between the normal geometric beam to the grating and the incident and passed geometrical rays, respectively. As d decreases to the edge of the lens of Fig. 4B can be seen that the outer rays have greater variance than rays near the center. Causing a reduction of the lattice period a certain way, all the rays can be directed to the th and vertical axes, respectively.

The geometry of the beam in the diffraction optical element DOE is illustrated schematically in Fig. 5. A monochromatic plane wave with a given wave length0in the air has an angle 0 with the optical axis of the diffractive optical element, which is provided in contact with a flat substrate with a refractive index (n). The diameter of the diffractive optical element is denoted by D, and the back focal length of the combination of the diffractive optical element, the substrate is denoted by f. For various combinations of the relations f/number and diameter D for a diffraction optical element, and the refractive index n of the substrate, the full width of the focal spot measured at half maximum intensity (FWHM) could be defined as follows. It was found that the full width of the focal spot measured at half maximum intensity varies between 0.33 μm and 0.42 μm on the optical axis and between 0.70 μm and 0.90 μm at the edge of the field of view. The intensity of the last rays on the optical axis was approximately 0.9, and the intensity of the last rays on the edge of the field of view of approximately 1/10 from the first. Thus, the full width of the focal spot measured at the level of half the and for refractive lenses in the form of microspheres, while the intensity decreases faster towards the edge of the field of view of the diffractive optical element. This, however, is an advantage, since for a given diameter of the diffractive optical element opens the possibility of a free choice relations f/number and the refractive index of the substrate, since both of these values will affect the diffraction-limited full width of the focal spot measured at half the maximum intensity. Another advantage of diffractive optical elements is that they have a slight curvature of field, so focus on the optical axis and focus on the edge of the field are approximately in the same plane. Analysis of the diffraction-limited characteristics of focus for the diffraction optical element in contact with a flat substrate shows that the diffraction optical element with a fixed diameter full width of the focal spot measured at half maximum intensity is inversely proportional to the refractive index of the substrate and is proportional to the ratio f/number of the diffractive optical element in the substrate.

Finally, should the ion optical element is strongly dependent on the wavelength of light.

Design of a data carrier in accordance with the present invention, which uses a diffraction

optical elements or lenses - zone plate constructed as described above will be discussed in more detail with reference to Fig. 6, which schematically illustrates a portion of a data carrier, with a dense matrix of diffractive optical elements on the surface of the data carrier. Each diffractive optical element acts as a small lens, and the incident light is focused, as mentioned above, and is directed to a memory area, i.e. the area bearing the information that is in the future for the sake of brevity will be referred to as bit-slice.

Every bit of information presents the material in a bitmap layer affects light or exposed to light falling on the material during phase lighting during data processing. Assuming, for example, that a data carrier such as is illustrated in Fig. 6, the light incident on the diffraction optical element in front, focuses on the rear side of the diffractive optical element, which is covered with a thin film of an alloy of tellurium. The last bit is a layer or Go high-intensity pulse of light during the phase of writing. The content in this part of the media data that is associated with each diffraction optical element, therefore, presents a set of transparent or opaque bit-distributed areas or structures in the bit layer, which is, for example, to appear bright or dark when read in transmitted light. Each provision of data on the data carrier is associated with a unique address, which you can access through the diffractive optical element during read and write in two independent steps. The position of a given diffraction optical element on the surface of the data carrier is defined by the coordinates x, y; for example, the location of the chromatic focus, relative to the origin on the media data and the position in the bit layer of the spots related to the corresponding diffractive element are determined by the direction of light incidence, which focuses on this point, however, for example, in normal polar coordinates . Thus, the full address must be x, y , .

In order to achieve storage densities as high as possible in the media, stains or data storage structures should be as small as possible, and they should be on" between groups of data storage structures, can be accessed through different but adjacent diffractive optical elements should be minimized. The latter requirement imposes a relationship between the configuration of the position of each data storage structures under each diffractive optical element, the shape and relative position of the diffraction optical element on the surface of the carrier. It should be noted that very little data storage structures or the spot size can be achieved by using diffractive optical elements, which is several orders of magnitude greater than the data storage structures. Moreover, a large range of sizes of diffractive optical elements can provide nearly the same average amount of data storage structures and, therefore, the same average local density of data storage in a bitmap layer.

In the latter case, a large diffraction optical element must be associated with a large number of provisions of the data storage structures, thus implying a more tightly spaced angular positions addressing the incident light during read and write. As will be discussed later for optimized media, increasing the size DEFRA diffractive optical element, and this should be weighed depending on a higher accuracy in the angular coordinate .

As an example, it should be noted that the diffraction optical element, which occupies an area of 2500 μm2and usually can reach 10,000 or more data storage structures, as illustrated above, has a diameter of 0.3-0.7 μm, and is divided into angular shifts addressing and up to 0.5-1.0o. If the linear dimensions of diffractive optical elements have been reduced by the factor N, then the angular separation between adjacent data storage structures should be increased by approximately the same factor, while the number of data storage corresponding to each of the diffraction optical element is reduced by the factor N2.

In some embodiments, embodiment of a data carrier in accordance with the invention, the recording and reading can take place through the interaction of light with a thin film, in close analogy with the known optical data carriers. Indeed, film, developed for known media type "write once - read many" (WORM) and rewritable media can be directly you who etenia from other known techniques is as the light is directed and focused onto the bit layer, and the consequences arising from this.

Record

During the recording of a short and intense pulse of light is sent to the assigned diffractive optical element with coordinates x, y in a given direction . To speed up the recording process, several or all areas related to the diffraction optical element are displayed simultaneously or in rapid succession, for example, via a pulse illuminated spatial light modulator (SLM) or a cluster of laser (laser, vertical cavity emitting surface, VCSEL), as illustrated in Fig. 7. The result of this action corresponds to the entry with parallel tracks on a large scale, which will be described in more detail subsequently. The permissible deviation of the alignment of the rays record in respect of each diffractive optical element depend on the specific design and performance parameters in each particular application, but generally are much wider than those used in conventional optical data storage schemes. In the latter case the tracking accuracy of the order of 1 μm in all three of the TA may be one or two orders of magnitude more free.

Reading

The physical layout of the data carrier, combined with a hierarchical (x, y) (, ) addressing, opens new possibilities for simple high-speed random access and data transmission. Instead of a sequential read bit line along the track through a sharply focused laser beam can be made large-scale parallel read by the image transfer large blocks of data directly from the media data on a matrix detector.

One embodiment of the invention is illustrated schematically in Fig. 8, where the light is collimated at an angle of incidence, is sent simultaneously to a large number of diffractive optical elements, prompting the media data to display the status bits of the address , each lit diffractive optical elements. The latter are usually spaced at relatively large intervals, 30-100 μm, on the surface of the data carrier and therefore can be easily solved by means of wide-angle optics with a large depth of field, which displays the status bits at the address on each diffractive optical element on a matrix detector, as illyustriruyutsya from flatness. The maximum depth of field of the optical system, which has a resolution of 50 μm at a wavelength of light of about 480 nm is 10 mm. on the other hand, if the status bits should be addressed direct mapping configuration bits in a simple flat layer without diffractive optical element, the bitwise spacing of less than 1 μm would entail the depth of field is approximately equal to 3 μm, and reading on a large scale for simultaneous display on a matrix detector would be almost impossible, even with the focusing servomechanism. A method that solves this problem is described in U.S. patent N 4745484 (J. Drexler and J. B. Arnold), which shows the timing sequence display on multiple spaced stages.

The image formed on the matrix detector under the action of light at an angle1,1covering the state of discharge at all addresses {x, y1,1} in the media within the field of view is transmitted to the electronic reader device for further processing, and the detector is cleared for a new cycle of reading this time at an angle reading2,2. In turn, the electronic view. The cycle repeats until then, until all the desired address in the data carrier does not matter.

The above readout circuit with angular multiplexing flat carrier at a first glance, such a holographic memory with angular multiplexing, and in some respects is similar to the scheme based on refractive or reflective structures that direct and focus light on the burnt film, as described in published international patent application N WO 91/11804 (P. E. Nordal). As will be described in detail in the following paragraphs, however, the use of diffractive optical elements in accordance with the present invention provides technological capabilities and benefits to productivity and profitability, which are otherwise not available.

In connection with consideration of the above-mentioned principle of the diffractive optical element DOE has demonstrated how it was possible to obtain a small focal spot defined by their full width FWHM, measured at half the maximum intensity. The size of the focal spots or full width FWHM, measured at half the maximum intensity, when using diffractive optical is STI data in this layer. Calculations of the relevant structures of the media data and operating parameters such as the wavelength of light, show that the spot size of the diffraction-limited or nearly diffraction-limited over large areas of space under each diffractive optical element. Under certain conditions, this means for example that you have correctly performed the diffraction optical element with a diameter of 50 μm illuminated by light at a wavelength of 450 nm, can create paraxial, i.e. on the optical axis, a focal spot with a diameter of 0.33 μm, measured at half the maximum intensity, provided that the ratio f/number is 1 and the refractive index of the substrate is equal to 1.6. At positions off-axis, i.e. the angle of incidence > 0oat the focal spot influence of aberration in the lens, and if = 30othe focal spot increases already up to 0.61 μm.

As already mentioned, the image field curvature is very small, if only diffractive optical element is constructed on a spherical surface in order to avoid coma. In this case, can be used contained in the dispersion properties of the diffractive optical element to correct the curvature of field.

which have no analogy when using refractive or reflective optical systems. This means that diffractive optics provides complete freedom of choice as the ratio f/number and the refractive index of the substrate, and thus, the size of the focal spots is sharply different from the case with a spherical refractive lenses.

As already mentioned, a striking aspect of diffractive optics is its very large variance, i.e. the focal length of the diffraction lens is strongly dependent on the wavelength of light. Thus, while the optical materials for refractive lens, the refractive index varies with wavelength, and it usually leads to a change in focal length of the lens on the relative value of 1% seems spectrum, the change of the diffraction lens in 40-50 times, corresponding to the inverse relationship between focal length and wavelength of light. This obviously has a negative value for those applications where a stable monochromatic light source is not available due to technical or price restrictions or where it is desirable to create images with polychromatic light. In the present invention can be used monochromatic light, and the allowable deviation of the wavelength for drives with the WPPT is iMovie lasers and light-emitting diodes (LED). Thus, with proper selection and variation of the wavelength, it becomes possible to shift the position of the focus within the substrate in a controlled manner. In the present invention it can be used in several ways.

Correction of curvature of image field

As is illustrated in Fig. 9a, the bit layer is flat, and the image in monochromatic light forms a spherical surface, as shown by the dotted lines. Thus, the focal spot created on a flat bitmap layer, are formed and are growing due to their position outside the optimal focal distance. As the focal length depends on the wavelength of light, it should be noted that it can be used to configure the wavelength of the incident beam of monochromatic light as a function of incidence angle in order to position the focus in bitmap layer, for example, as shown in Fig. 9D. The basic principle can be implemented either through a matrix of light sources with a fixed wavelength, or by using a tunable light sources.

Simultaneous access to multiple bitmap layers by setting the wavelength of the

As the focal length can be configured maintains the x depths, as shown in Fig. 10. The main factor that makes this scheme is applicable in practice, is a large dispersion in the diffractive optical element. To avoid crosstalk between the different layers, they must be separated at least by a distance s, Fig. 10. The minimum separation distances s depends on several factors, such as characteristics of the recording thin film layer bit, the desired contrast and acceptable level of crosstalk. The latter depends, in turn, increased the content data in each focal spot, for example grayscale coding (gray level). Thus, in designing for the maximum possible relationships between data density and capacity of the read/write there is a tradeoff between code levels in gray-scale coding, on the one hand, and simultaneous recording/reading multiple bitmap layers, on the other hand.

The way the parallel read data involves the use of optical filters.

A simple assessment can be made with reference to Fig. 10, whereas that can be used focal spot negligibly maloa, which passes through the adjacent bit-slice, will be

dfs= DS/f (2)

where D is the diameter, a f is the focal length of the microlenses. Since the focal length of the diffraction optical elements is inversely proportional to the wavelength , it is possible to obtain the change in wavelength value

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Now you can require that dfsit was so large that the light intensity bit layers that are out of focus, has been reduced by some factor concerning intensity at the optimum focal point. Neglecting absorption in the bitmap layer and assuming that dfs= 2.0 μm, a reduction of intensity in the multiplier 16, if the minimum diameter of the focal spot is 0.5 μm, the diameter D=50 μm can be obtained

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This means that in this particular case you want to change the wavelength by 4%, that is, for example, increasing the wavelength from 480 nm to 500 nm. If the wavelength of light is within the visible or near visible region of the spectrum, it can be used a number of bit of the layer or layers of storage, each of which is addressed by light at the wavelength corresponding to this layer, for example, assuming 4% separation between adjacent which is 14 layers, that gives a 14-fold increase in storage capacity compared to the single layer storage, provided that the data density in each layer is the same in both cases.

This concept of multi-layered storage resembles a certain known patterns of data storage in two or more parallel layers on the discs, but with an important difference. In the present invention, the addressing of each layer is carried out by setting the wavelength of light, while the known schemes are all based on the mechanical positioning of the optical read/write by means of the actuator controlled by a servo-mechanism. Thus, in the present invention eliminated the difficulties associated with the mechanics, and, together with the setup wavelength provides extremely fast random access.

A well-known problem multilayer storage is that the light must cross lying in his path a bit layers as light propagates in the medium to get to the corresponding bit layer or storage layer. As light propagates from this layer to the detector, the same lying in his path layers must be crossed again (when read in the reflected light of the processes in transmitted light), this problem was first encountered developers of IBM, which concluded that in practical systems can be feasible 10 layers by careful selection of the reflection coefficient in each layer (read from the data medium in reflected light). It is reasonable to expect that the reading of the data carrier in the transmitted light will be less demanding in this respect.

Optical data carrier in accordance with the present invention can be designed so that ten layers of storage with a thickness of 2 μm together form a layered structure or a stack of layers that extend over 10 microns on each side of the Central layer. Within this volume can be made or produced a number of different structures.

(1) Each layer can be created by recording the beam forming data storage structures, i.e. the bit the points that define the bit layers inside the initially homogeneous unit thickness of 20 μm, in this case, each data storage structure will actually be a small element of volume corresponding to the volume element with high intensity focused recording beam.

(2) In another case, the word is and you can give, for example, through the introduction of dye molecules specific spectral characteristic, which corresponds to the wavelength at which the light enters at the optimum focus in this particular layer of storage. So, this characteristic can be selective absorption in a narrow band in the unfixed state of the storage layer, changing to low absorption in the recorded spot (discoloration). If the absorption band is narrow and do not overlap, all other layers except the right one, will be transparent to light at this wavelength, thus eliminating problems of contrast and interference.

With regard to use of diffractive optical elements, they are currently available from several manufacturers and come with the quality and size required for the present invention.

From the foregoing it will be clear that the optical storage device in accordance with the present invention using diffractive optical elements makes possible the true bulk storage and access to data in a memory area where data can be stored in arbitrarily selected, but is ambiguous addressable positions in the amount of memory, or m is m can be made arbitrarily and space.

1. Optical data storage device that contains the memory location of data generated transparent homogeneous base material and a number of optically active treatments in the form of diffractive optical elements (DOE) adjacent to one side of the field data memory, in which each of the diffraction optical elements configured to focus a beam of light incident on one or more points to the data memory, each of which corresponds uniquely addressable cell of the data storage structures, which must be formed or is formed by the data storage structure in the area of data memory, and/or focusing the redirected beam of light or the emitted light radiation from this point or these points on a point outside the optical data carrier, characterized in that the diffractive optical element is formed with a manageable, step changes phase.

2. Optical drive data under item 1, characterized in that the diffractive optical elements (DOE) are lens - zone plate.

3. Optical drive data under item 1, characterized in that the memory data is formed between the transparent surface of the optical elements is formed on the surface layer.

5. Optical drive data on p. 3, characterized in that the diffractive optical elements embedded in the surface layer.

6. Optical drive data on p. 3, characterized in that the diffractive optical elements (DOE) is formed as a unit with the surface layer.

7. Optical drive data on p. 3, characterized in that between the surface layer and the memory data is formed of an opaque layer, and mentioned opaque layer is able to break down the absorption of energy of radiation.

8. Optical drive data under item 1, characterized in that the data storage device is designed in the form of a tape, disc or card, and diffractive optical elements are placed on the surface of the above-mentioned tape, disc or card.

9. Optical drive data under item 1 or 8, characterized in that the diffractive optical elements (DOE) placed in rows and columns, thus forming a two-dimensional matrix of diffractive optical elements.

10. Optical drive data under item 1, characterized in that the memory area data contains one or more layers that form one or more separate planes genenerated layer storage dye molecules in each layer of storage have different spectral characteristics corresponding to the wavelength of the light beam, focused on the storage layer diffractive optical element (DOE).

11. Optical drive data on p. 10, characterized in that one or more of the storage layers are partially reflecting whether partially transparent layers.

12. Optical drive data under item 10 or 11, characterized in that the layers of storage, depending on the wavelength of light, are either reflective or transparent layers.

13. The method of recording data in an optical data storage device that contains the memory location of data generated transparent homogeneous base material and a number of optically active structures in the form of diffractive optical elements (DOE) adjacent to one side of the field data memory, in which each of diffractive optical elements (DOE) made with the ability to focus the beam of light incident on one or more points to the data memory, each of which corresponds uniquely addressable cell of the data storage structures, which must be formed or is formed by the structure of grantecan from this point or these points on the point outside of the optical data storage device, wherein the form of diffractive optical elements with controlled, manual changes phase, direct the laser beam on the diffraction optical element located on an optical data storage device, focusing thus mentioned laser beam mentioned diffractive optical element at a particular point in the area of data memory, whereby the energy released from the above-mentioned laser beam in the focal point, produces a physical or chemical change in the material in a clean area of the data memory at this point and thus creates a data storage structure, which is assigned to the data item, the value of which corresponds to the degree of physical or chemical changes in the material in the above-mentioned data structure, and referred to the rate of change determined by the modulation mentioned laser beam in accordance with a given modulation procedure.

14. The method of recording data in an optical data storage device that contains the memory location of data generated transparent homogeneous base material and a number of optically active structures in the form of a diffractive optical the ski element DOE) made with the ability to focus a beam of light, falling on one or more points to the data memory, each of which corresponds uniquely addressable cell of the data storage structures, which must be formed or is formed by the data storage structure in the area of data memory, and/or focusing the redirected beam of light or the emitted light radiation from this point or these points on a point outside the optical data storage device, the method involves the use of laser with tunable wavelength, characterized in that the form of diffractive optical elements with controlled speed change phase, direct the laser beam on the diffraction optical element on the optical data storage device, set the wavelength mentioned laser beam so that the said laser beam to focus mentioned diffractive optical element at a particular point in the area of data memory, and whereby the energy released from the above-mentioned laser beam in the focal point, produces a physical or chemical change in the material in a clean area of the data memory at this point and creates thus a data storage structure, which is assigned to the data item value is wound data, moreover, the above-mentioned rate of change determined by the modulation mentioned laser beam in accordance with a given modulation procedure.

15. The method according to p. 14, characterized in that the wavelength of the laser beam is set so that the degree of configuration defines one or more arbitrary storage layers in a homogeneous material basis.

16. The method according to p. 15, characterized in that the wavelength of the laser beam is set so that said laser beam is focused to a point in a storage layer, where it forms the data storage structure.

17. The method of reading data in an optical data storage device that contains the memory location of data generated transparent homogeneous base material and a number of optically active structures in the form of diffractive optical elements (DOE) adjacent to one side of the field data memory, in which each of diffractive optical elements (DOE) made with the ability to focus the light beam incident on one or more points to the data memory, each of which corresponds uniquely addressable cell of the data storage structures, which must be formed or is formed by the structure of chronischen from this point or these points in the point outside of the optical data storage in which the data storage device includes data storage structures formed by the method according to p. 13, characterized in that the form of diffractive optical elements with controlled, manual changes phase, direct the laser beam on the diffraction optical element on the optical data storage device, focusing thus the laser beam on a specific data storage structure in the area of data memory, whereby the energy released from the above-mentioned laser beam in the focal point, produces optically detected response of said data storage structures so that the said detected response corresponds to the value of the data item, stored in the data storage structure, and the above-mentioned optically detected response focus mentioned diffractive optical element to an optical detector mounted outside the mentioned optical data storage.

18. The method according to p. 17, in which the data storage device contains molecules of a fluorescent dye embedded in the base material, characterized in that to read the data used light with a wavelength of, custom in spectral characteristics is different, contains the memory data formed of a transparent homogeneous base material and a number of optically active structures in the form of diffractive optical elements (DOE) adjacent to one side of the field data memory, in which each of diffractive optical elements (DOE) made with the ability to focus the light beam incident on one or more points to the data memory, each of which corresponds uniquely addressable cell of the data storage structures, which must be formed or is formed by the data storage structure in the area of data memory, and/or focusing the redirected beam of light or the emitted light radiation from this point or these points in a point outside the optical data storage in which the data storage device includes data storage structures formed by the method according to any of paragraphs.14 to 16, characterized in that the form of diffractive optical elements with controlled, manual changes phase, direct the laser beam on the diffraction optical element on the optical data storage device, configure the wavelength mentioned laser beam so that the said laser beam to focus on opredelenno is Zernovo beam in the focal point, produces optically detected response of said data storage structures, so that the detected response corresponds to the value of the data item stored in the data storage structure, and the above-mentioned optically detected response focus mentioned diffractive optical elements on the optical detector mounted outside the mentioned optical data storage.

20. The method according to p. 19, in which the data storage device contains layers of storage with molecules of a fluorescent dye embedded in the base material, which form the layers of storage, characterized in that to read the data used light with a wavelength to be tuned on the spectral characteristics of the molecules of a fluorescent dye formed in each layer of storage.

21. The way parallel recording data in an optical data storage device that contains the memory location of data generated transparent homogeneous base material and a number of optically active structures in the form of diffractive optical elements (DOE) adjacent to one side of the field data memory, in which each of diffractive optical elements (DOE) made with the possibility focusservicesemail cell data storage structures, which should be formed or is formed by the data storage structure in the area of data memory, and/or focusing the redirected beam of light or the emitted light radiation from this point or these points in a point outside the optical data storage device, wherein the form of diffractive optical elements with controllable speed phase changes, send two or more laser beam emitted by the laser device, which contains two or more separately generated by laser elements through the optical device and with different angles of incidence on the diffraction optical element located on an optical data storage device, set the wavelength of each laser beam so that the said laser beam to focus mentioned diffractive optical element on the same plane, and the said plane corresponds to a particular storage layer in the memory area of the data, whereby the energy of each laser beam in the focal point, causes a physical or chemical change in the material in a pure layer of data storage in each focal point in said plane, thus creating the e each data structure of some data item, the value of which corresponds to the degree of physical or chemical changes in the above data structure, and referred to the degree of change is determined by the modulation referred to the respective laser beam in accordance with a given modulation procedure.

22. The way the parallel read data in the optical data storage device that contains the memory location of data generated transparent homogeneous base material and a number of optically active structures in the form of diffractive optical elements (DOE) adjacent to one side of the field data memory, in which each of diffractive optical elements (DOE) made with the ability to focus the light beam incident on one or more points to the data memory, each of which corresponds uniquely addressable cell of the data storage structures, which must be formed or is formed by the data storage structure in the area of data memory, and/or focusing the redirected beam of light or the emitted light radiation from this point or these points in a point outside the optical data storage device, which is applied the method according to any of paragraphs.14 - 16 write data or the way the operating optical elements managed, step changes phase, send two or more light beam from the lighting device, which contains two or more separately excited by a light source with fixed or tunable wavelength, and referred to the wavelengths of light rays either fixed or rebuilt by the optical device on one or more diffractive optical elements on the drive data, focusing thus mentioned light rays on certain data storage structures in the area of data memory, whereby the energy of each laser beam in the respective focal point, produce optically detected responses from the mentioned data storage structures and the above-mentioned optically detected responses focus through another optical device located on the opposite side of said data storage device, and an optical detector elements in the optical detector device, and the detected optical responses correspond to the data values assigned mentioned respective data storage structures.

23. The method according to p. 22, characterized in that use multiple light sources in the lighting optical device, and focus of individual rays of light through one or more diffractive optical elements under different angles of incidence for parallel generation of optically detected response from a number of data storage structures, corresponding to the same diffraction element.

24. The method according to p. 23, characterized in that place light sources in the lighting device with the possibility of formation of the matrix of the lighting elements.

25. The method according to p. 23, characterized in that at the same time set up a separate light rays from the light source at various wavelengths for parallel generation of optically detected response from a number of data storage structures, which are located in different planes or layers stored in the optical memory, resulting in addition to a parallel reading of data stored in the data storage structures in the same plane or layer storage, reach parallel readout for data stored in data storage on different planes or layers of storage.

26. The method according to p. 22, characterized in that for reading data to optical filters.

 

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FIELD: optical data carriers.

SUBSTANCE: optical data carrier has at least two layers, each of which is a substrate with recording film, on which optically discernible code relief is formed with information elements readable via laser radiation, which contain elements with optical limiting property. Method for manufacture of optical multilayer data carrier includes manufacture of at least two layers, each of which has optically discernible code relief with laser radiation readable information elements, which are formed of substance, having property of optical limiting. Method for multilayer optical recording of data, in which information is recorded by forming and moving pulses of laser radiation flow along surface of recording film in formed tracks, filled with substance, having optical limiting property, or components for synthesis of substance, having property of optical limiting. Method for reading from optical multilayer data carrier, including forming of laser radiation flow, its focusing at read layer with optically discernible code relief with information elements, containing substance, having property of optical limiting, modulation of light signal reflected from code relief by frequency and amplitude.

EFFECT: higher efficiency.

4 cl, 3 dwg

FIELD: data carriers.

SUBSTANCE: in optical data carrier, including track, including multiple recesses, formed on basis of first data being subject to recording, and platforms, formed between adjacent recesses, these recesses are recorded with deformation on basis of second data. First and second data are synthesized and played for realization of sound playback with broad frequency range. Also, first data are recorded with possible playback by means of common disc player. Playback of first data is controlled by second data for protection of recorded data.

EFFECT: higher efficiency.

6 cl, 44 dwg

FIELD: optical data carriers.

SUBSTANCE: device has cation dye or mixture of cation dyes with optical characteristics, changed by means of recording beam, an at least one substance with functions of damper and phenol or substituted phenol with one hydroxide group or more, while it additionally contains phenol or substituted phenol in form of phenolate ion, forming a portion of anions for dye cations, as a stabilizer. Data carrier can contain anionic metal-organic thyolene complex as damper, which forms other portion of anions for dye cations.

EFFECT: higher stability, higher durability, lower costs.

5 cl, 1 tbl, 3 ex

FIELD: optical data carriers.

SUBSTANCE: device has tracks, each of which is comprises multiple recesses, formed on basis of first data, meant for recording, and areas between recesses. Multiple recesses are displaced from track center on basis of second data, at the same time recesses cross central position of track with given periodicity. First data may be recorded analogically to compact disk data. Second data may be separated from signal of track tracking error. Second data may be used for copy protection in relation to first data, while amount of first data, which can be recorded on carrier, does not decrease when recording second data, and as a result of recesses displacement range being set within limits of preset value in range, wherein no track tracking displacement occurs, first data can be played back by existing players to provide for compatibility of playback.

EFFECT: higher efficiency.

8 cl, 12 dwg

FIELD: optical discs that can be manufactured with the use of one and the same process parameters.

SUBSTANCE: the optical disc for recording and/or reproduction has an area of an initial track, user's data area and an area of the final track. Each of the areas of the initial track, user's data and final track includes recording grooves and fields between the recording grooves produced in them. The recording grooves and the fields between the recording grooves include curves produced at least on one side of the recording grooves and fields between the recording grooves. The curves in the area of the initial track, in the area of the user's data and in the area of the final track are modulated by means of various methods of modulation.

EFFECT: enhanced reliability of signal recording and reproduction.

64 cl, 18 dwg

FIELD: technologies for manufacturing optical disks for storing information, in particular, development of fluorescent substance and method for manufacturing WORM-type optical disks based on it.

SUBSTANCE: fluorescent multilayer substance on basis of organic dyers with polymer linking component for optical data storage disks of type WORM with fluorescent reading, in accordance to first variant, has two-layered light-sensitive polymer composition inside a track, formed in transparent film made of refractory polymer. First layer has hard solution of fluorescent dyer. Second layer is a combined solution of light absorbent and fluorescence extinguisher. Polymer linking component belonging to first layer has substantially reduced melting temperature in comparison to polymer linking component belonging to second layer. In accordance to second variant, fluorescent multilayer substance is made sensitive to polarization of laser beam, enough for controlling processes of reading and recording information in a fluorescent WORM disk due to polarization of laser beam. Also provided is method for manufacturing one-layered optical disk of type WORM, basically including forming of a fluorescent layer in two stages. Firstly, lower semi-layer is formed, containing fluorescent dyer, and then - upper semi-layer, containing non-fluorescent dyer, or at the beginning lower semi-layer is formed, containing non-fluorescent dyer, and then - upper semi-layer, containing fluorescent dyer. Non-fluorescent dyer is selected in such a way, that its absorption area mainly coincides with spectral absorption area and/or fluorescence area of fluorescent dyer.

EFFECT: improved efficiency of recording/reproducing systems and information preservation on basis of WORM-type optical disk with fluorescent reading.

3 cl, 2 dwg, 3 ex

FIELD: engineering of information carriers and appropriate reading and recording devices.

SUBSTANCE: variants of information carrier contains information about its configuration recorded thereon as well as information about inertia moment of current information carrier. Recording device contains means for determining physical characteristics of utilized information carrier by reading information about configuration and information about inertia moment from wobbulated groove of information carrier, and recording control means, applying corrections for performing recording process in accordance to physical characteristics of information carrier. Reading device contains means for determining physical characteristics of information carrier by reading information about configuration and information about inertia moment, and recording control means, applying corrections for performing reading operation in accordance to physical characteristics of information carrier.

EFFECT: simple and precise process of determining physical characteristics of information carrier, possible adjustment of reading and recording operations.

4 cl, 93 dwg

FIELD: engineering of devices for information storage.

SUBSTANCE: device for information storage contains disks with information carrying layer mounted with possible rotation relatively to common axis, disks rotation drive, reading and/or recording head, positioned on the side of end of one of edge disks and directed towards the latter by its active zone, and also drive for moving aforementioned head in plane, parallel to rotation plane of disks. Information carrying layer at least on one disk, positioned on the side of head, is made with forming of window, transparent for signal, emitted and/or read by head and having shape matching movement trajectory of head, and disks rotation drive is made with possible independent rotation of disks and holding in position, providing for positioning of window in front of active zone of head.

EFFECT: increased efficiency.

8 cl, 4 dwg

FIELD: engineering of data carrier, and of recording and reading devices, compatible with such a data carrier.

SUBSTANCE: each variant of aforementioned data carrier contains recording track, formed by a stream of recesses on the surface of carrier, data of recess represent information recorded on it, which contains main data and sub-code. In accordance to one of variants, information about physical characteristics of current data carrier is recorded in sub-code. In accordance to other variant, data carrier contains multiple individual reading/recording zones, physical characteristics of which are different, and each one of aforementioned zones contains zones for input, zones for program and ones for output, while in sub-code of input zone of each one of aforementioned zones, information about physical characteristics of appropriate individual reading/recording is recorded as well as information about starting position of input zone of next individual reading/recording zone. Each one of variants of recording device contains a certain device for determining physical characteristics of aforementioned data carrier by reading information about these from sub-code, and each variant of reading device contains aforementioned determining device and device for controlling reading.

EFFECT: increased quality of reading and writing of information.

6 cl, 94 dwg

FIELD: optical recording technologies, namely, engineering of two-layered optical disks with high recording density, and of devices for recording/reproducing from them.

SUBSTANCE: two-layered optical disk with high recording density contains first recording layer and second recording layer, positioned on one side of central plane, dividing the disk in half along thickness, close to surface, onto which light falls. First thickness of substrate from surface, onto which light falls, to first recording layer has minimal value over 68,5 micrometers, second thickness of substrate from surface, onto which light falls, to second recording layer has maximal value less than 110,5 micrometers, while refraction coefficient is within range 1,45-1,70.

EFFECT: minimization of distortion of wave front, provision of possibility of more precise recording of signals onto optical disk or reproduction of signals from optical disk.

8 cl, 10 dwg

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