Cholesteric photoactive compound for generating laser emission
FIELD: physics, photographic material.
SUBSTANCE: invention pertains to polymer cholesteric photoactive compounds, which can independently generate laser emission when irradiated with laser light. Such a compound can be used, for example, in photonics, optoelectronics and telecommunication systems. The cholesteric photoactive compound for generating laser emission consists of cholesteric liquid crystal, photoactive additive and laser dye. The liquid crystal used contains conjoint polymer n-(6-acrylyl oxycapril hydroxyphenyl)-n-methoxy benzoate with cholesterine-11-acrylyl undecanoate, containing molar quantities between 30% and 25% of the cholesterine-11-acrylyl undecanoate links. Photoactive additive used is 2.5-bis(4-methoxy cynnamoyl)-1.4;3.6-dianhydro-B-sorbitol, while the laser dye used is 4-(dicyano methylene)-2-methyl-6-(4-dimethyl amino styryl)-4H-pyran. The invention improves the temporal and thermal stability of the compound, and allows for its use at room temperatures and at lower temperatures as well. Sensitivity of the compound to external effects is also lowered.
EFFECT: increased thermal stability of photoactive compounds and lower sensitivity to external effects.
2 ex, 1 dwg
The invention relates to the field of polymer cholesteric photoactive compositions, capable under the influence of irradiation of the laser light independently to generate laser radiation. Such compositions can be used, for example, in Photonics, optoelectronics, telecommunications systems, as well as in other areas, which are traditionally used laser technology.
Known cholesteric photoactive composition for generation of laser radiation on the basis of low-molecular weight liquid crystal (GCR) and laser dye (P.V.Shibaev, R.L.Sanford, D.Chiappetta, V.Milner, A.Genack, A.Yu.Bobrovsky, "Light controllable tuning and switching of losing in chiral liquid crystals" // Optics Express, 2005, 13, 7, 2358).
The disadvantage of this arrangement is the difficulty of its application, due to the liquid state of aggregation of the composition, requiring the creation of a special hermetic cells that protect the composition from external influences.
Known cholesteric photoactive composition for generation of laser radiation on the basis of polymerizable mixtures of mesogenic monomers and laser dyes (Pview, Nijana, Awesomsauce, Wpimages. "Generation of laser radiation in polymer cholesteric grids" // high-Molecular compounds. 47A, 6, 961, 2005).
The disadvantages of such compositions are the difficulty of retaining a uniform mono-domain planar the nd patterns in the polymerization mixture of monomers in the composition and poor reproducibility of the process of obtaining a uniform mono-domain structure, leading to poor performance of the composition.
Closest to the claimed is cholesteric photoactive composition for generating laser radiation, consisting of a cholesteric GCR (representing a mixture of nematic GCR unknown composition produced by the company Merck under the trade name (brand) Zli is-1695, chiral photoactive additive manufactured by the company Merck under the trade name (brand) Zli is-811, transforming, in addition, the nematic phase GCR in cholesteric) and laser dye n-decyloxy-n'-centerpanel, in the following ratio, wt.%:
(A.Chanishvili, G.Chilaya, G.Petriashvili, R.Barberi, R.Bartolino, G.Cipparrone, A.Mazzulla, L.Oriol "lasing in dye-doped cholesteric liquid crystls: two new tuning strategies" // Advanced Materials, 2004, 16, No. 9-10, 791) prototype.
The disadvantages of the known compositions are its instability over time and its sensitivity to external influences (temperature, mechanical, photochemical, and so on), due to the liquid state of aggregation of the composition, which leads to uncontrolled changes in its optical properties. For example, cooling the composition below 15°it leads to Cree is tallization and loss of performance properties.
An object of the invention is the creation of a cholesteric photoactive composition characterized by high temporal stability (years), thermal stability, including the possibility of its use at low temperatures down to -20°and low sensitivity to external influences.
This technical result is achieved by the fact that in the known cholesteric compositions for generating laser radiation, consisting of a cholesteric JKR, photoactive additives and laser dye, as JKR use a copolymer of n-(6-acryloyloxyhexyloxy)-n-methoxybenzoate (AA) with cholesteryl-11-akiloyunlari.com (HA), containing from 33 to 35 mol.% links HA, as photoactive additives use of 2,5-bis(4-methoxycinnamyl)-1,4; 3,6-dianhydro-D-sorbitol (Sorb), as a laser dye using 4-(dicyanomethylene)-2-methyl-6-(4-dimethylaminostyryl)-4H-Piran, (DCM) in the following ratio, wt.%:
|The copolymer of AA HA||98-99|
Synthesis of copolymer of AA HA, having the structural formula shown in the drawing, described in (Niebaum, Diss. on saisc. academic degree Cand. chem. Sciences. Moscow, Moscow state University, 1988). what was experimentally detected, to obtain good results only suitable alloy containing from 30 to 35 mol.% links HA. Brednikova molecular weight (MP) of such alloy may vary within wide limits, for example from 10 to 30 kDa.
Synthesis of photoactive additives Sorb described in the literature (monitoring computerized. Bobrovsky, N.I.Boiko, V.P.Shibaev "New chiral-photochromic dopant with variable helical twisting power and its use in photosensitive cholesteric materials // Molecular Crystals and Liquid Crystals 2001, vol.363, 503).
The proposed laser dye DCM, produced under the trademark of DSM known. (Ulrich Brackmann, Lambdachrome Laser Dyes", D-37079 Goettingen, Germany, 2000, p.185).
The use of the proposed composition for the generation of laser radiation based on the introduction of small additives of laser dyes, which under the action of an external laser pump (external laser) are starting to generate laser radiation.
Photoactivity proposed composition depends on the composition and may be manifested as occurrence of lasing under irradiation optical cell with a composition by ultraviolet light, and the disappearance of laser generation under the action of UV radiation.
Laser generation of the proposed compositions recorded in the cells representing the two glass plates coated with polyimide coating, grated in one direction to create a planar orientation. The cell gap created with the help of two Teflon speicherbereich thickness.
Emission is observed in the direction perpendicular to the film plane, in the region of wavelengths corresponding to the edge of the photonic bandgap, i.e. on the border strip of selective reflection of light λmax.
The advantage of the proposed composition explain the following examples.
Cholesteric photoactive composition is prepared from a copolymer of AA HA with Mn=12 kDa, containing 33 mol.% links HA, with a glass transition temperature of 26°C, the temperature of the enlightenment 122°and a wavelength selective light reflection 565 nm. The composition is obtained by dissolving 98.5 mg (98.5 wt.%) the above CPF, 1.0 mg (1.0 wt.%) Sorb and 0.5 mg (0.5 wt.%) DCM in 0.5 ml of chloroform with subsequent removal of the chloroform in a drying Cabinet at 60°and drying in vacuum at a temperature of 120°C.
For manufacturing cell using glass plates coated with polyimide coating, grated in one direction to create a planar orientation. The cell gap created with the help of two Teflon spacers with a thickness of 20 μm. Filling the cell composition is realized by means of capillary forces when heated compositions and cells up to 150°C. thereafter, the cell is annealed for 1 h at a temperature of 112°10° below the temperature of enlightenment, then cooled to room temperature at a rate of 1° /min
For optical pumping of a laser dye, i.e. for the generation of laser radiation, use of a pulsed radiation of the second harmonic (532 nm) of Nd3+YAG laser operating in the modulation mode q-factor (pulse duration 5 NS, repetition rate 5 Hz). The pumping radiation is focused on the sample by a lens with a focal length of 28 cm, giving a focal plane spot size of 0.3 mm2.
The incident laser beam is directed at an angle of 45° to the normal plane of the cell and is generated in the direction normal to the radiation detected through the system, including fiber optic cable - CCD spectrometer (spectral resolution of 0.6 nm) - based computer.
Prepared cell filled with planar-oriented cholesteric composition, does not have a laser generation. Photoactivity this composition is manifested in the fact that UV irradiation of the cell with light of a wavelength of 365 nm for 3 h leads to the shift of the peak selective reflection of light by 30 nm in the wavelength region of the spectrum and the appearance of several narrow bands of laser generation (599.5 nm, 610.3 nm and 642.4 nm).
Check the intensity of the laser generating composition and its spectral range, conducted after 6 and 12 months after its preparation, showed the stability of the above operational characteristics. Received the song because of its solid aggregate state has low sensitivity to external influences.
The experience carried out analogously to example 1, but using alloy containing 35 mol.% links HA, with a glass transition temperature of 27°C, the temperature of the enlightenment 124°and a wavelength selective light reflection 558 nm. The composition is obtained by dissolving 98.0 mg (98.0 wt.%) the above CPF, 1.0 mg (1.0 wt.%) Sorb and 1.0 mg (1.0 wt.%) DCM in 1.0 ml of chloroform with subsequent removal of the chloroform in a drying Cabinet at 60°and drying in vacuum at a temperature of 120°C.
Prepared cell filled with planar-oriented cholesteric composition at a temperature of 0°has a laser generation with a strip of 639 nm.
Photoactivity this composition is manifested in the fact that UV irradiation of the cell with light of a wavelength of 365 nm for 3 h leads to the shift of the peak selective reflection of light in the wavelength region of the spectrum and the extinction of laser generation.
Check the intensity of the laser generating composition and its spectral range, conducted after 6 and 12 months after its preparation, showed the stability of the above operational characteristics. The resulting composition due to its solid aggregate state has low sensitivity to external influences.
Thus, the proposed composition really helps to increase a temporary camera is lnost composition until at least 1 year, to reduce the sensitivity of the composition to external influences and to improve its thermal stability, including the possibility of its use at room and lower temperatures.
Cholesteric photoactive composition for generating laser radiation, consisting of a cholesteric liquid crystal photoactive additives and laser dye, characterized in that the liquid crystal used is a copolymer of n-(6-acryloyloxyhexyloxy)-n-methoxybenzoate with cholesteryl-11-akiloyunlari.com containing from 30 to 35 mol.% links cholesteryl-11-acrylamidoglycolate, as photoactive additives use of 2,5-bis(4-methoxycinnamyl)-1,4;3,6-dianhydro-D-sorbitol as a laser dye using 4-(dicyanomethylene)-2-methyl-6-(4-dimethylaminostyryl)-4H-Piran, in the following ratio, wt.%:
|copolymer of n-(6-aryloxyalkyl)-|
|n-methoxybenzoate with cholesteryl-|
FIELD: chemistry; passive Q-switch crystal growing process.
SUBSTANCE: production process for growing crystals of galium scandium gadolinium garnets is based on Czochralski process, which implies crystal growing from initial molten batch, which is congruently melting gallium scandium gadolinium garnet produced by 3-phase synthesis, doped with magnesium oxide and chromium oxide. These oxides provide for 2.0×1020-2.6×1020 atoms/cm3 concentration of cromium and magensium cations in melt during the first crystal growing, in argon with 14-17% of carbon dioxide, pressure in chamber being 1.3-2.0 atm. For the second, third and subsequent growths, an initial batch amount equal to previous crystal weight, cromium and magnesium content in batch being determined according to formula (СCr×СMg)/1020 = 0.5÷2, where СCr is at least 5×1019 atoms/cm3, is added to the crucible.
EFFECT: provides for required Q-switched mode, continuous or pulse, within wavelength range of 1,057-1,067 mcm.
FIELD: laser engineering.
SUBSTANCE: proposed method for manufacturing solid-state laser element involves production of porous tetraethoxysilane matrix using sol-gel synthesis, proportion of source reaction mixture components being as follows, volume percent:: tetraethoxysilane, 30-33; water, 24-27; concentrated nitric acid, 2-3; formamide, 16-18, ethanol, the rest up to 100; this mixture is poured after hydrolysis at room temperature in rectangular neutral dishes, each one is first tightly covered with neutral film. In two or three days holes are made to evaporate liquid products of reaction mixture; gel obtained in the process is dried out for 1-3 weeks at 40 °C to produce solid porous matrix. The latter is given heat treatment by heating at rate of 30 °C per hour from room temperature to 600 °C followed by cooling down at rate of 50 °C per hour to room temperature. First alternative method includes preparation of vinyl ethoxysilane sol solution after heat treatment of porous matrix, proportion of components being as follows, volume percent: vinyl triethoxysinale, 52-54; 0.5% solution of concentrated nitric acid, 15-17; ethanol, the rest up to 100; hydrolysis stage is followed by adding rhodamine 101T dye in amount of 0.51-0.52 g/l to sol solution, and mixture obtained is introduced by way of impregnation into pores of mentioned tetraethoxysilane matrix, the latter being placed into reservoir filled with this mixture. Reservoir is covered with neutral film having small hole, then dyed sol solution penetrated into pores and that remaining outside of matrix is subjected to polycondensation and drying at room temperature for two or three weeks. After that matrix is extracted from surrounding mixture at definite visually determined initial moment of mixture thickening, matrix surface is cleaned mechanically and by means of ethanol, dried out at 40 °C for 23-25 h, whereupon processes of impregnating this matrix with dyed sol solution, polycondensation, matrix extraction from mixture, cleaning, and drying is repeated. Another alternative method includes addition of phenalemine 512 dye in amount of 0.34-0.35 g/l in sol solution upon hydrolysis stage and mixture obtained is introduced by impregnation into pores of mentioned tetraethoxysilane matrix.
EFFECT: enhanced efficiency and generating photostability dictating service life of solid-state laser element.
FIELD: crystal growing technologies.
SUBSTANCE: invention relates to technology of growing crystals for passive laser shutters used in modern lasers operated in IR spectrum region. Crystals are grown according to Chokhralsky method from initial stock melt containing metal oxide mixture, namely produced via solid-phase synthesis gallium-scandium-gadolinium garnet of congruently melting composition with magnesium and chromium oxide additives assuring concentration of chromium and magnesium cations in melt 2.0·1020 to 2.6·1020 at/cm3. Process is carried out at cell pressure 1.4 atm in argon and carbon dioxide medium with carbon dioxide content 14-17% by volume. Invention makes it possible to grow perfect crystals of gallium-scandium-gadolinium garnets alloyed with chromium cations, which are characterized by absorption coefficient above 5 cm-1 within wavelength 1.057-1.067 μm generation range.
EFFECT: achieved required Q-switching mode in continuous and pulsed operation conditions.
FIELD: production of optical laser materials used as optical medium for transmitting, generating, and converting photon radiation at optical-signal different frequency and power.
SUBSTANCE: source mixture of metal fluorides has base in the form of one or more fluorides out of group of alkali-earth metals and alloy additive; the latter and base are capable of producing homogenous solid solution of fluorite structure at molar proportion of 50-90/50-1; source mixture has components with fluorine-ion excess introduced therein. Proposed laser fluoride ceramic production process includes hot pressing of source mixture of crushed fluoride fractures of alkali-earth and rare-earth metals using active fluorinating agent. Fluorinating agents are obtained by their gaseous liberation during decomposition of source components under pre-evacuation and heating conditions. Source mixture used for the purpose incorporates mentioned composition. Hot pressing is conducted at temperature of minimum 900 °C. Additional fluorination of charge is conducted by means of gaseous CF4 supplied from outside.
EFFECT: ability of producing highly transparent laser material suited to transfer, generate, and convert photon radiation at different frequencies and power of optical signals, including those unattainable for monocrystals.
5 cl, 1 tbl
FIELD: laser engineering; advanced lasers for fiber-optic communication lines, optoelectronics, and spectroscopy.
SUBSTANCE: proposed tungsten-tellurium glass based film material for lasers activated by Er3+ ions is made in the form of film and applied to molten crystal substrate in high-frequency magnetron spraying process. For spraying use is made of target incorporating TeO2, WO3, and ER2O3 oxides; target is sprayed onto substrate heated to 250 - 350 °C in argon-oxygen mixture environment, whereupon film obtained in the process is annealed in oxygen at 130 - 390 °C.
EFFECT: enhanced chemical stability, lifetime, and quantum yield of photoluminescence of film.
6 cl, 2 dwg, 1 tbl
FIELD: polymer materials.
SUBSTANCE: invention relates to technology of manufacturing transparent profiled articles, for example, containers and bottles. Transparent article comprises continuous polyester matrix containing at least one incompatible filler dispersed therein. Incompatible filler provides domains in polyester matrix, each of them having particular size thereby forming a size range for domains contained in an article. To create turbidity, domain sizes lie within the range between about 400 nm and about 700 nm. Once size range is determined, a light absorbing substance can be selected to absorb light within a wavelength range, which at least essentially overlaps the preliminarily found domain size range.
EFFECT: facilitated finding substance masking turbidity of a polymer article.
20 cl, 12 dwg, 3 tbl
FIELD: organic chemistry, chemical technology.
SUBSTANCE: invention relates to novel oxazine compounds of the formula (I): wherein X means carbon atom; R1 and R2 mean hydrogen atom; n = 0; A and A' mean independently of one another: (a) linear or branched (C1-C12)-alkyl, (C3-C12)-cycloalkyl; (b) unsubstituted or monosubstituted aryl groups. Also, invention relates to a method for synthesis of photochrome oxazine compounds of the formula (I). Invention provides synthesis of novel compounds and a method for their synthesis used as photochrome compounds.
EFFECT: improved method of synthesis.
10 cl, 1 tbl, 9 ex
FIELD: optical materials.
SUBSTANCE: invention relates to radiation-sensitive compositions with variable refraction coefficients allowing novel model with refraction coefficient distribution to be obtained, in particular optical material used in optical electronics and information representation devices. Invention discloses emission-sensitive composition with variable dielectric permittivity containing decomposable compound (A), non-decomposable component (B) including inorganic oxide particles resistant to acid or base originated from acid or base source (C), and radiation-sensitive degradable substance (C), wherein refraction coefficient nA of decomposable compound A and refraction coefficient nB of non-decomposable compound B lie in one of following relationships: nB-nA ≥ 0.05 (1) and nA-nB ≥ 0.05 (2), amount of component B ranges from 10 to 90 wt parts based on 100 wt parts of summary amount of components A and B, and amount of component C ranges from 0.01 to 30 wt parts based on 100 wt parts of summary amount of components A and B. Model obtained from indicated composition allows one to vary in a simple way refraction coefficients thereby achieving sufficiently large difference between them and their stability irrespective of application conditions.
EFFECT: expanded possibilities in optical representation of information.
12 cl, 3 tbl, 7 ex
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: color-forming compositions and recording material.
SUBSTANCE: claimed composition includes developer containing urea-urethane compound and colorless or light colored leuco dye. Recording material based on this composition also is proposed.
EFFECT: color-forming compositions with improved image conservation ability and increased image intensity.
21 cl, 14 tbl, 153 ex
FIELD: rubber industry; production of the vulcanizable rubber mixture on the basis of the hydrogenated butadiene-nitrile caoutchouck.
SUBSTANCE: the invention is pertaining to production of the vulcanizable rubber mixture on the basis of the hydrogenated butadiene-nitrile caoutchouck used for manufacture of rubber-technical products efficient at the temperatures up to 150°С. The vulcanizable rubber mixture contains (in mass): the hydrogenated butadiene-nitrile caoutchouck - 70-95, the acrylate caoutchouck - 30-50, sulfur - 0.5-1.2, quaternary ammonium base - 2-6, sulfonamide Ц - 0.5-1.5, thiuram Д - 1-2, metallic stearate - 2-4, zinc oxide - 3-5, industrial carbon - 40-50, the stearic acid - 1-2, the antioxidant - 3.0-3.8. The technical result of the invention consists in reduction of the mixture viscosity, increase of the heat-resistance and the aggressive mediums-resistant properties with the simultaneous decrease of the residual compressive deformation.
EFFECT: the invention ensures the reduced mixture viscosity, the increased heat-resistant and the aggressive mediums-resistant properties at the simultaneously decreased of the residual compressive deformation.
3 cl, 2 tbl