Ar coating

 

(57) Abstract:

Usage: optical instrumentation to create optical elements made of semiconductor materials, including IR laser systems. The inventive antireflective coating type C1H2In where P - substrate with a refractive index of from 2.2 to 4.0, P - a quarter-wavelength at the operating wavelength layer with a low value of the refractive index of the fluoride, a quarter-wave layer with a high value of the refractive index of zinc sulfide or zinc selenide, K1and K2a multiplier less than one, between the substrate and the coating introduced adhesion layer of zinc sulfide or zinc selenide optical thickness (0.1 to 0.2)/4, and the layer with low refractive index is made of bismuth fluoride. 1 C.p. f-crystals, 1 Il., table 1.

The invention relates to an optical instrument, in particular for the optical coatings and can be used to create a walk-through optical element (OE) of the semiconductor materials (PMM) with antireflection coatings for infrared (IR) radiation, which can be used in the process of laser systems.

Poluprovodnikov fundamentals MA, working in the infrared region of radiation, including technological laser systems [1] With a number of positive properties, MRP have a relatively large value of the refractive index (from 2.2 to 4.0), which leads to significant losses of radiation in passing the MA due to the reflection. For this reason, the urgent need for a strong and effective antireflection coatings for MRP, especially those in powerful IR laser systems.

Traditionally for antireflection coatings on MRP was used such film-forming materials (POM) as SrF2, BaF2, PbF2, ThF4, ZnS, ZnSe and others [2] Among fluoride having a low refractive index, only fluoride thorium (ThF4) not soluble in water and forms a dense amorphous layers. The lowest absorption among them has fluoride lead-free (PbF2), however, this material provides high water resistance of the coating. In addition, as PbF2and ThF4have high toxicity, corresponding to the first group of risk [3] that degrades the environment in the production of coatings and waste disposal. POM SrF2and BaF2having the acceptable value of the refractive index, do not provide necessary is defamiliarised the principle of enlightenment MA from MRP is the use of design antireflection coating type N, where P substrate and N quarter-wavelength at the operating wavelength of the layer with a refractive index close to the value n , where npthe refractive index of the substrate. An example is the design of antireflection coatings for MA from zinc selenide (ZnSe), where the quarter-wave layer is made of barium fluoride (BaF2) [4] In order to improve the stability of the coating additionally produce the implantation of silicon ions to a depth of 0.04 0.08 thickness of the coating with the exposure dose of radiation 2 CL/m2after which produce annealing at 470 570 K during 600-2400 C.

The main positive feature of this analog is the improvement of the mechanical stability of the coating by increasing adhesion. The main disadvantages of this coverage remains low resistance and a large reflection coefficient is about 5% of the Latter is a consequence of the significant differences in the refractive index BaF2(n 1,4) from the conditions of perfect enlightenment ZnSe, with np2,4, for which 1.55V.

Another similar design is antireflection coating MA from ZnSe [5] where a quarter-wave layer made of PbF2. Its main characteristics the following are the high toxicity in the production, lack of moisture and not enough small value of the reflection coefficient, which according to modern requirements of the MA for the process of laser systems is r0,3%

As the prototype is useful to consider the design of antireflection coatings for the MA of ZnSe in the article [6] of the form C1H2In which N quarter-wave layer at the working wavelength of ThF4or BaF2In a quarter-wave layer with a high value of the refractive index of the sulfide (ZnS) or zinc selenide, K1and K2a multiplier less than one, depending on the magnitude of the refractive index used in the construction IND. The total optical thickness of such coatings does not exceed a quarter wavelength. The principal advantage of this design before discussed earlier counterparts is to achieve (according to the calculation of the reflection coefficient of zero was received less than 0.02% absorption in the coating at the wavelength of 10.6 µm amounted to 0.03% of the Main disadvantages of the prototype are high toxicity (in the case of ThF4or the increased absorption and lack of moisture (in the case of BaF2).

The aim of the invention avluca environmental conditions in the production of coatings and disposal of waste with a low reflection coefficient, low absorption and high strength.

This goal is achieved by the fact that in the antireflection coating type C1H2In where P substrate with a refractive index of from 2.2 to 4.0, N quarter-wavelength at the operating wavelength (l) a layer with a low value of the refractive index of the fluoride, a quarter-wave layer with a high value of the refractive index of zinc sulfide (ZnS) or zinc selenide (ZnSe), K1and K2a multiplier less than one, between the substrate and the coating introduced adhesion layer of ZnS or ZnSe optical thickness (0.1 to 0.2) l/4, a layer with low refractive index is made of fluoride, bismuth (BiF3), and the values of the multipliers TO1and K2depend on the size of the refractive index of the substrate material and are given in table deviations.

In the drawing conditionally (in cross section) given the design of the proposed ar coatings, where the substrate 1 is deposited adhesion layer 2 of ZnS or ZnSe optical thickness (0.1 to 0.2) l /4, then a layer BiF33 optical thickness TO1l/4, over which is applied a layer of ZnS or ZnSe 4 optical thickness TO2l/4.

The proposed solution has the following salient PR because of the specific features of the condensation layers BiF3[7] have typical stress strain with subsequent partial relaxation in the aging process, which leads to cracking and peeling of the layers. Given the low adhesive layer BiF3between it and the substrate, we have introduced adhesion layer. The material of the adhesion layer was applied the following requirements: low absorption, low refractive index and the insolubility in water. In addition, the adhesive layer must have a compressive stress to compensate for the tensile stress in the layer BiF3. As our investigations have shown that such requirements were satisfied layers of ZnS and ZnSe optical thickness (0.1 to 0.2) l/4. At the greater thickness of the adhesive layer increases the absorption and deteriorates the adhesion characteristics of the antireflection coating.

The second layer with low refractive index is made of bismuth fluoride. In the literature it is known to use BiF3as the interference layer is transparent in the region of 0.3 -14,0 µm [8] However, its application in the design of the IR antireflection coatings for MRP and working when exposed to intense laser beams in the technical and patent literature is not detected. This SIP is not soluble in water, izvodstve coatings and waste disposal. According to the results of our investigations layers BiF3at a wavelength of 10.6 µm have a refractive index of about 1.56 to, and absorption layers obtained under optimal conditions, 510 b-4. A significant distinguishing features form a new set of features, unknown in the patent and technical literature.

The proposed solution is implemented as follows.

Based on the magnitude of the refractive index MRP, choose from the table the value of the multiplier K1and K2depending on the SIP ZnS or ZnSe. Ar coating is applied on the optically polished substrate by thermal evaporation and condensation in vacuum, for example on domestic vacuum unit type WU-2M. First, on a substrate applied adhesive layer of ZnS or ZnSe optical thickness (0.1 to 0.2) l/4, then put a layer of BiF3optical thickness TO1l/4 and at the end put a layer of ZnS or ZnSe optical thickness TO2l/4.

Practically, we have manufactured Windows and lenses of ZnSe for technological CO2laser power up to 3 kW. Implemented cover design P 0,15 ZnS, 0,7 BiF3, 0,15 ZnS thermal evaporation in vacuum on installing WU-2M.a window or lens with double-sided antireflective coatings t99,0% threshold beam strength of not less than 10 j/cm2thermoresistance of not less than 200oC, resistance to moisture and mechanical stress of the coating corresponded to group I on OSTS-1901-85.

We also deposited antireflection coatings on optical elements of cadmium sulfide (CdS), which has at a wavelength of 10.6 μm, the refractive index n of 2.2, from silicon and gallium arsenide (GaAs) having a refractive index of 3.45 (l 2,94) and 3.3 (l 10.6 μm), respectively, as well as from Germany (n 4,0 at 10.6 μm). In all cases, with an accuracy of 0.1% reflection of these coatings meet the values specified in the table, and strength characteristics were the same high.

Thus, the proposed design of antireflection coatings turned out to be universal for MRP having a refractive index of from 2.2 to 4.0. Made antireflection coating for reflectivity and absorption was not worse than the prototype, had a high strength and toxicity, at least on the order of less dangerous.

Sources of information

1. Golubev, C. S. and other Practical aspects of using the IR transparent materials in technological CO2lasers,Preprint No. 14, , Troitsk, 1986.

2. Physics of thin films. So 8, Ed. by G. Huss and others M. Mir, S. 36.

4. USSR author's certificate N 1800428 A1, 07.03.93. Bull. N 9.

5. Takeo Miyata // SPIE, 1986, v. 650, p. 131 -140.

6. Rudisill J. E. et al. // Apll. Opt. v. 13, N 9, p. 2075 2080.

7. Gusev A., and other Optical and physical properties of films of bismuth fluoride, //weapons of mass destruction, No. 5, 1990, S. 55.

8. Moravec T. J. et al. //Appl. Opt. v. 18. N 1. p. 105 110.

9. Harmful chemicals. Inorganic compounds of the elements V-VIII groups. Handbook Ed. by C. A. Filova, L. Chemistry, 1989.

1. Ar coating type PC1NK2In optical elements made of semiconductor materials, where P substrate with a refractive index of from 2.2 to 4.0, N quarter-wavelength at the operating wavelength layer with a low value of the refractive index of the fluoride, a quarter-wave layer with a high value of the refractive index of zinc sulfide or zinc selenide, K1and K2multipliers less units, characterized in that between the substrate and the coating introduced adhesion layer of zinc sulfide or zinc selenide optical thickness (0.1 to 0.2)/4, and the layer with low refractive index is made of fluoride, bismuth, and when the refractive index of the substrate n 2,2 K10,75 3% and20,10 3% n 2.410,72 5% and20,12 5% n% n 3,4510,39 30% and20,36 30% when n is 4.0 TO10,26 20% and20,49 20%

2. The floor under item 1, characterized in that the substrate material with a refractive index n of 2.2 use cadmium sulfide, with n 2.4 zinc selenide, with n 2.7 cadmium telluride, with n 3,0 X, n, 3,3 gallium arsenide, n 3.45 the silicon with n 4,0 germanium.

 

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FIELD: polymer materials.

SUBSTANCE: invention provides composition containing from about 50 to about 80% of component selected from group consisting of di(meth)acylate of ethoxylated bisphenol A, di(meth)acylate of non-ethoxylated bisphenol A, di(meth)acylate of propoxylated bisphenol A, epoxy(meth)acrylates of bisphenol A, and mixtures thereof; from more than 0 to about 30% of component selected from group consisting of tetrahydeofuryl (meth)acrylate, isobornyl (meth)acrylate, cyclohexyl (meth)acrylate, and mixtures thereof; from more than 0 to about 15% of component selected from group consisting of dipentaerythritol penta(meth)acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, tri(meth)acrylate of ethoxylated or propoxylated trimethylolpropane, tri(meth)acrylate of ethoxylated or propoxylated glycerol, pentaerythritol tetra(meth)acrylate, bis-trimethylolpropane tetra(meth)acrylate, dipentaerythritol hexa(meth)acrylate, and combinations thereof. Such composition is suited to manufacture eyeglass lenses.

EFFECT: expanded possibilities in manufacture of polymer-based lenses, including multifocal ones.

21 cl, 3 tbl, 18 ex

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