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1.3 Properties of optical materials for field of a spectrum 10 microns. Measure for a select of optical materials of powerful lasers

For manufacturing of optical devices visible and short-range IK - fields use traditional optical materials - glasses. As a rule, they (except for specially developed halkogenidnyh glasses) are unsuitable for use in long-range and medial IK - gamuts owing to uptake on oxygen ions.

Materials, in field 9÷11 a micron, it is convenient to part transparent on fiziko - to chemical properties on following groups:

1) the ionic monocrystals;

2) semiconductor monocrystals;

3) halkogenidnye glasses;

4) optical ceramics;

5) polycrystalline materials;

6) non-linear crystals of threefold linkings.

The basic measure for a select of optical materials of powerful laser systems, we have short formulated as follows:

1) stability to action of an environment and possibility of manufacturing of high-precision optical surfaces (performance of this requirement is possible if material parametres are maintained after the long-term touch with a surrounding medium; and the material possesses high values of hardness, ultimate strength, a yield strength, the module the Ship's boy);

2) good teplofizicheskie properties: high values of a thermal conduction, a heat capacity, temperatures of fusion and low quantity of a linear expansion coefficient;

3) optical properties:

Peakly low absorption constant in working field of a spectrum;

Small exponent of a refractive;

Low values of photoelastic constants;

Transparency in visible light;

In a material there should be immersing inserts and microflaws in the size ≥ 100 And;

4) the parametres of a material set forth above in a working range of temperatures, should to depend on temperature feeblly, whenever possible;

5) the "know-how" of materials and their optical processing should be, as it is possible, more simple and inexpensive (thus it is necessary to consider, that products can have the considerable dimensions); it is desirable also that it was ecologically pure.

By working out of optical devices of monopulsing laser systems performance of requirements i.i. 2, For, 36, Zv and 4 to a used material it is not binding.

Long-term experience shows what to pick up an optical material for powerful CO2 - the laser, completely satisfying to the above-stated measure, it is practically impossible. Requirements 1-5 are rather manifold and rigid, and properties of optical materials known now are far from an ideal. Features of these materials force to search for conciliatory proposals, to perfect expedients of cultivation of crystals and their optical processing, to carry out optimum selection of a material in dependence as from concrete application in the given laser device, and from features of use of the laser. Enough profound knowledge of the physicochemical properties of necessary materials and their responses to beam actions depending on concrete requirements of operation therefore are required. In the given section of operation are systematised and physical properties of the materials interesting for represented below examination are analyzed, and also prospects of their application for manufacturing of the transparent optical devices powerful CO2 - lasers are considered.

Rather widely in the long-range and medial personal computer - fields the ionic crystals are applied. For the analysis of properties of these crystals, they are convenient for parting on three basic subgroups [101, 193, 194]:

1) fragile, water-soluble shchyolochno-HALOID monocrystals with structure of chloride sodium (NaCl);

2) soft, plastic and gigroskopichnye crystals with structure of chloride caesium (CsCl);

3) plastic, metallopodobnye on mechanical properties,
Moisture resistant haloids of argentum and thallium.

From materials SHCHGK viewed further possess the best optical properties: a small absorption constant, a low exponent of a refractive and a high transparency in visible field [30-35]. These crystals are not toxic. As SHCHGK are the first optical materials, found application in IK - to the technician by present time the stable industrial technology of cultivation and optical processing of these monocrystals is created. They have a good transparency and are used in a wide spectroscopic gamut from UF to IK spectrum fields. SHCHGK are usually grown up by method Kiropolusa. In operations [96, 183], for example, it was informed on working out of the automated technology of cultivation of monocrystals of chloride of kalium in diameter to 600 mm and weight to 140 kg. Their serial release in NPO "monokristallreaktiv" [96, 183] has been organised.

Unfortunately SHCHGK possess essential deficiencies. They it is very good rastvorimy in water. Therefore, at humidity of air in more than 35 %, them opticheski the handled surface intensively adsorbs an atmospheric moisture [30 35, 110, 193], that causes sharp magnification of an absorption constant

pripoverhnostnogo a stratum also conducts to decrease in a threshold of optical firmness of a product. At SHCHGK the bad mechanical properties. They are fragile and very easily break up on planes spajnosti even at a small loading. SHCHGK have low hardness, that essentially impedes manufacture of high-quality optical surfaces. At temperature slight increase even rather small loading leads to plastic strain. Nevertheless, they can be applied even at 300 - 400 o C under controllable requirements of operation.

Nevertheless, the optics from SHCHGK is polished to a high class of optical cleanliness on special technology under condition of controllable humidity. For degradation prevention the polished surfaces of a material should be protected from humidity influence. Radiation action causes occurrence in SHCHGK colouring centres. The linear expansion coefficient 10 times exceeds corresponding value at the majority of glasses. The given deficiencies extremely impede making vakuumnoplotnyh linkings that is necessary for use as windows of gas lasers. SHCHGK possess a low thermal conduction and are inclined to treshchinoobrazovaniju even at small thermoshock.

As around 10 microns monocrystals of fluorides of alkaline metals have appreciable uptake for IK optics they usually practically are not used. From all SHCHGK more often in the field of 10 microns monocrystals NaCl and KCl are used. Among SHCHGK, transparent in the field of 10,6 microns, crystals of chloride of sodium possess the best mechanical properties, they have in this group the highest "natural" threshold of optical firmness in pulsed conditions [129-132], and, hence, are most perspective for use in powerful monopulsing lasers. Though absorption constant NaCl a little above, than at KCl, however, at use in pulsing lasers this odds practically has no value. For the continuous lasers of low power use of chloride of sodium also can appear more preferable, than KCl as owing to some best mechanical properties NaCl it is handled better, than KCl.

Now monocrystals of chloride kalium are one of the basic materials of optics of powerful continuous and pulse-frequency lasers. Absorption constant KCl can reach, under corresponding requirements of cultivation, quantity (6÷8)? IO ' 5см ' 1. However, the crystals which are grown up on usual technology, developed in the fiftieth years of the last century, have β ≤ IO ' 3см ' 1 [59, 60]. It was found out, that near to 10 microns value of an absorption constant shchyolochno - haloid crystals is spotted by concentration in them kislorodosoderzhashchih impurities (SO4 ^^, SO3 ^^ NO2 - NO3 ^, OH ^, NH2 - HCO3 - C2O2) [43-45, 87, 89, 195, 196]. Oscillations of communication O-H cause uptake in field 2÷4 a micron, and oscillations of communication O-C - in field 9÷10 a micron [43-45]. C occurrence of so-called RAP-technology (Reactive Atmosphere Processing), developed in Huges Research Laboratory [43-45], and also in laboratory of physics of crystals AN of Hungary [197], it was possible to grow up crystals KCl with an absorption constant, close to a multiphonon limit. This method is grounded on clearing of a melt of initial raw materials from kislorodosoderzhashchih impurities by means of pyrolysis CCl4. Cultivation of monocrystals was yielded by vertical method Bridzhmena in atmosphere of pure gases Not or CO2.

On the observational samples of bromic kalium (KBr), gained RAP - a method, will reach the lowest absorption constant - 5? IO ' 6см ' 1 [43]. Therefore, despite considerably worst physicochemical properties in comparison with NaCl and KCl, this material is considered perspective for use in the continuous lasers.
However the technology of reception of large-sized crystals while widely is not developed by this method. Therefore monocrystals KBr which is serially grown up in industrial requirements, having β ~ 4? IO ' 3cm ' 1 [30, 59], that above, than in kalium and sodium chlorides, and considerably yielding to them on the physicochemical properties, in the up-to-date laser systems are not used.

The technology of cultivation of monocrystals of firm solutions KCl - KBr is developed. At their examination it was found out, that they have rather low absorption constant at satisfactory mechanical properties, however the thermal conduction of these samples has appeared more low, than at pure KCl and KBr [41, 59].

Others fragile SHCHGK, transparent in the field of 10 microns, as a rule, it is ready more gigroskopichny and have the worst mechanical properties [101, 193]. Optical firmness of these crystals in pulsed conditions much more low, than NaCl [129-132]. In the industry they practically are not applied.

CO2 - the laser with shchyolochno-HALOID crystals chapter 5 is devoted examination of features of interaction of an impulse of radiation.

Crystals CsI and CsBr (a subgroup plastic SHCHGK) differ low hardness and high hygroscopicity, are rather plastic. Their absorption constant more than at kalium chloride, and teplofizicheskie is even worse than property, than at SHCHGK. Therefore, though they also are released by the industry for optics long-range IK - a gamut and for manufacturing stsintsilljatorov particles of high energies, in CO2 - lasers these crystals practically are not used.

Argentum haloids also are soft and plastic, suppose all methods of processing by pressure, practically not rastvorimy in water [101, 193, 198, AZ]. Now them apply to manufacturing of the light guides used on the average IK - a gamut [198]. A large deficiency of haloids of argentum is propensity to a photolysis at action by radiation visible and, especially, ultra-violet gamuts, however, this process manages to be attenuated considerably by a doping [193]. Crystals of chloride argentum (AgCl), alloyed by mercury, are much more inconvertible against action of a daylight without appreciable deterioration of optical properties in IK - fields. Now optical fibers for a gamut make 10 microns by vytjagivanija of monocrystals of firm solution AgCl - AgBr (KPC - 13) which are a little less inclined to a photolysis, than pure AgCl [198].

Galogenidy thallium are in many respects identical on the physicochemical properties to argentum haloids, however in optics, despite a little higher miscibility in water, they are applied much more often, because of the best mechanical properties [193, 198] and bolshej stability to action UF - radiations.

The industry releases large-sized monocrystals of firm solutions TlCl - TlBr (usually termed - КРС-6) and TlBr - TlI (КРС-5). These monocrystals, thanks to rather high photoelastic constants, are perspective in optical-acoustic devices, that, however, is a deficiency for application in laser windows. Nevertheless, long-term and laborious operation on technology of reception of monocrystals KPC has allowed to gain crystals with very low absorption constant on a wave length 10,6 microns - 5? IO ' 5см ' 1 [83]. This effect is gained thanks to the deep clearing of initial raw materials. Despite a low threshold of occurrence of optical inhomogeneities, they are sometimes used both in pulsing, and in the continuous laser systems when application of water-soluble optics is intolerable. Besides low optical firmness, their application is restricted to high toxicity, plasticity, the worst, than at SHCHGK, mechanical, teplofizicheskimi and, partially, optical properties, and as consequence, unsatisfactory quality of optical processing. However, after occurrence of industrial production CVD ZnSe crystals КРС-6 have appeared are practically superseded from the personal computer - optics owing to ready worst physicochemical properties. Nevertheless, monocrystals КРС-5 are still applied to manufacturing of optical-acoustic devices, and also optics of the long-range personal computer - a gamut since in a gamut 30-50 microns are transparent only KPC - 5 and iodide caesium.

Fluorides shchyolochnozemelnyh metals are widely used for manufacturing of optical devices of the medial personal computer - a gamut thanks to rather successful combination of the physicochemical properties [101 193]. Unfortunately, except barium fluorides - BaF2 (β = 0,15÷0,17 sm ' 1) and strontium - SrF2 (β = 0,4 sm ' 1), almost all of them are opaque on a wave length 10,6 microns [139, 140, 193]. However, thanks to a small exponent of a refractive fluorides often use at drawing of the interference coats [101 193, 199]. By the way, it is most interesting thereupon chetyryohftoristyj thorium (ThF4). Coats from this material have rather high optical firmness and are widely applied to manufacturing of optics of CO2-lasers [25]. In Russia on use of linkings
Thorium in the industry essential restrictions that is related by that this material formally is registered among radioactive though has very major half-life period - l, 39xlθ10лет [200] are imposed.

Drawing 1.4 - the Transmission spectrum of monocrystal BaF2 [201]

Barium fluoride is grown up in vacuo by method Stokbargera. It is rather rigid material, but thus has high sensitivity to heatstrokes. Fluoric barium does not react with atmospheric steams of water at temperature to 5 OO0C, possesses good mechanical properties, is not bad handled. In a dehydrated medium the material can be used up to 800oC. Monocrystals BaF2не are toxic, possess high radiative firmness, have a small exponent of a refractive (p = 1,39).

In drawing 1.4 the transmission spectrum of a monocrystal plate of fluoride of barium of 10 mm is given by thickness. It is well visible, that losses on uptake considerably grow, since λ ~ 9 microns. On a wave length 9,55 microns (CO2 - lasers rather easily, with small losses, are reconstructed for radiation generation on this wave length, that is important for some applications) uptake in BaF2заметно more low, than on λ = 10,6 microns. Therefore the given material can be recommended to use in CO2 - the lasers radiating on λ = 9,55 microns. Barium fluoride is sometimes applied for
Manufacturing of optical devices (diameter to ~ 100÷180 mm) monopulsing СО2 - the lasers radiating on λ = 10,6 microns when its rather high losses on uptake are not noises for operation.

For the solution of some specific applied problems making of the multispectroscopic radiators working in a gamut 0,53 - 10,6 microns is required. However the suitable material for manufacturing of the transparent optical device of such multispectroscopic radiator, does not exist. One of variants of the solution of this problem: to narrow this gamut a little, carrying out generation in СО2 - the laser on a wave length 9,55 microns and to use for a deduction of radiation optics from barium fluoride.

The following group of materials, suitable for manufacturing of the transparent optics СО2 - lasers, semiconductor crystals form: diamond, germanium (Ge), gallium arsenide (GaAs) and group A11Bv linkings ι. For the given materials practical lack of a miscibility in water, good mechanical and teplofizicheskie properties is characteristic. However, optical properties at them, as a rule, worse, than at SHCHGK. Semiconductors, owing to rather small breadth of a forbidden region, possess exponential dependence of an absorption constant on temperature (the equation (1.10)). In section 2.3 our observational effects of examination of dependence β106 (T) for germanium monocrystals are given. In the same place the various factors influencing uptake of monocrystal germanium in IK - fields are in more details viewed. To number of operational deficiencies of many semiconductors (Ge, GaAs, CdTe) it is possible to carry lack of a transparency in visible field.

Silicon monocrystals (Si), possessing fine mechanical and teplofizicheskimi properties, practically cannot be used for manufacturing of the transparent optics СО2 - lasers as in field 10÷ll the micron in them is observed rather appreciable lattice uptake [101, 193]. However they are widely used for manufacturing of substrates of high-quality interference mirrors with a reflectivity of 99,5 % and even more (section 1.4 see).

From all materials practically applied to manufacturing of optics СО2 - lasers, monocrystal germanium (Ge) has the highest hardness that allows to shape of it high-precision optical details. Products from Ge are convenient in operation. They do not interreact with an atmospheric moisture, are not toxic,
Are strong, have good teplofizicheskie properties. Optical details from germanium are well clarified by ONE-LAYER coats ZnS OR AS2S3 (to 98 %). Of germanium make the semitransparent mirrors working both without the interference coats, and with them, high-precision Fabry-Perot etalon, optical-acoustic devices and other optical details [30, 31, 193, 202-223]. The Most important scope of germanium - optics teplovizionnyh cabinets of a gamut of lengths of waves 8 - 14 microns used in systems of a passive thermal imaging, systems of infrared prompting, devices of night vision, fire-prevention systems [224, 225]. Germanium also is used for manufacturing of MNPVO-ELEMENTS for spectroscopy, effective beam splitters with a gear transmission of 50 % without necessity of the subsequent coat. Ge also it is widely used as a substrate for manufacture of light filters.

Because of presence of sharp temperature dependence of an absorption constant germanium application in the continuous lasers is restricted. Windows from Ge well work at power densities 100÷250 Вт/см2 if their effective cooling [30 is provided, 31]. Optical properties

Germanium monocrystals very strongly depend on concentration of the free carriers and a relation between electron concentrations and electron defects [А28]. Now crystals with β = 0,015 sm ' 1 are gained, at the lattice uptake βpe1=0,01 sm ' 1. The superficial uptake - 2βllol, = 0,0009 sm ' 1. These values are close to

To technological limit of possibilities of a material [А28, 79-81]. To action of radiation powerful pulsing CO2 - the laser sections 2.3, 2.4 and chapter 4 are devoted examination of optical properties of monocrystals of germanium and their firmness.

In gallium arsenide (GaAs), at compensation by chrome to a specific resistance 107÷108Омхсм, it is possible to lower quantity of an absorption constant to 0,002 sm ' 1. To temperature 3OO÷4OOoC this value grows slowly enough. Fine mechanical and teplofizicheskie properties, stability to environment action telescope GaAs in number of the most perspective materials for manufacturing of the transparent optics continuous CO2 - lasers [30, 31,42, 55, 61, 82, 91, 98-100, 155, 226-228]. Windows from GaAs if there is a cooling, do not collapse at a power density of the focused radiation to 40 кВт/см2. Application GaAs is restricted to difficulties of processing of toxic materials and complexity
Alignments because of a blackness in a visible gamut. Occurrence in the market of optical devices from CVD selenida the zinc which technology of reception has reached industrial level, has sharply lowered volumes of application GaAs in laser optics. In a relation the price - quality selenid zinc was surpassed by gallium arsenide, first of all, thanks to a transparency in a visible gamut, that sharply simplifies alignment process.

Drawing 1.5 - the Transmission spectrum selenida zinc [229]

Drawing 1.6 - the Transmission spectrum of the polished window from CVD ZnSe in the thickness of 5 mm in a gamut 400 - 1100 nanometers [230]

Semiconductor linkings of group A11Bvimogut to crystallise both in cubic, and in hexagonal singonii [194]. Sulphides concern them, selenidy and zinc and cadmium tellurides. For these materials it is characteristic rather
Small absorption constant in the field of 9-11 microns which feeblly enough depends on temperature as at these materials breadth of a forbidden region more than 2-3 ev. They possess quite good mechanical, teplofizicheskimi and climatic properties and are rather perspective for use in the continuous lasers. Crystals cubic singonii are isotropic. All semiconductor linkings of this type (except cadmium telluride) are transparent in visible field of a spectrum, at least partially. Unfortunately, there are the considerable problems at cultivation of cubic monocrystals of these linkings, even at diameter 2÷3 sm, owing to phase transition in a firm phase and propensity initial shihty to a dissociation at rise in temperature.

Most perspective of crystals of group A11Bvischitajutsja CdTe and ZnSe which absorption constant can to reach at existing technology quantities 10 ' 4÷10^3см ' 1 [30, 31, 59, 84, 92]. Interesting physical properties can appear at crystals ZnTe which while are rather feeblly studied. Are explored as well crystals of firm solutions of group A11Bv ι, for example, zinc selenida-telluride. Technological problems at cultivation of monocrystals ZnSe have been bypassed by reception of polycrystals selenida zinc of optical quality by chemical sedimentation from a gas phase (CVD - a method). This technology is developed and successfully implanted in industrial production. For today CVD ZnSe is the basic material for manufacturing of devices of the transparent optics technological СО2 - lasers [21, 30, 59, 232, 233]. In drawings 1.5 and 1.6 transmission spectrums selenida zinc are given, and in drawing 1.6 properties of a material in short-wave field of a spectrum that is necessary for understanding of its possibilities at designing of multispectroscopic radiators are in details shown.

In table 1.1 are given property CVD ZnSe yielded at institute of chemistry vysokochistyh of substances by it of G.G.Devjatyh [229].

Has appeared, also technology gazofaznogo chemical sedimentation of sulphide of zinc (ZnS) from zinc and hydrogen sulphide steams (CVD) with the subsequent high-temperature gazostaticheskim pressing. In effect, the new optical material, transparent in visible and HK - fields and possessing good mechanical properties is gained. Unfortunately, on an absorption constant in gamut CVD ZnS interesting us (βι o, 6 ~ 2.0? IO ' 1см ' 1) considerably yields
selenidu zinc [233-241].

Table 1.1 - Properties CVD selenida zinc [233]

For applications in aviation IK - systems of the forward review selenid zinc it is insufficiently good because its mechanical properties do not allow to maintain the loadings arising at hyperacoustic velocities. Created for the solution of these problems sulphide of zinc does not suit developers because of rather high uptake. In operation [243] it is informed on making of a new double-layer composit optical material on the basis of CVD ZnS - ZnSe («Tuftran»). A bottom is stratum ZnSe having good optical properties. C an outer side there is stratum ZnS in the thickness of 1 mm yielding selenidu of zinc on the optical
To properties, but having much the best mechanical properties. In operation [242] it is informed on making of domestic analogue of this material. In drawing 1.8 their transmission spectrums are given. Unfortunately, this material hardly will find application in powerful lasers.

Drawing 1.7 - Transmission spectrum CVD - sulphide of zinc [235]

Drawing 1.8 - Comparative performances of a gear transmission «Tuftran» and a double-layer composite of Joint-Stock Company "ИНКРОМ" (are designated by colour badges) [242]

In operation [244] it is informed on making of new perspective materials IK - optics - firm solutions halkogenidov zinc ZnSxSe1.x. Regulating a relation
Between S and Se in a material, it is possible to optimise a relation between optical and mechanical properties of a material.

A series of oxygen-free glasses from which in a gamut 8÷14 the micron possesses the best properties Ge28Sbι2Se6o [245 is developed for application in medial and long-range IK - fields, 246]. These glasses do not interreact almost with an atmospheric moisture, are well handled, the technology of their reception allows to cook large-sized preparations, but thus possess a number of essential deficiencies: are toxic, fragile, are afraid of thermal shocks, have low values of a thermal conduction and emolliating temperature, are opaque in visible light, have rather high absorption constant. Oxygen-free glasses are interesting to that, manipulating a composition, it is possible to change quantity of an exponent of a refractive in very wide limits. Thanks to it, on the basis of such glasses it is possible to create strong effective interference coats [245].

Stekloobraznyj tryohsernistyj arsenic (As2S3), despite a high absorption constant, is recommended in operation [247] for making of the strong interference vlagozashchitnyh coats on metal mirrors. Thin film As2S3способна the long-term time to protect a surface from action of an atmospheric moisture and has high enough optical firmness.

It is known, that polycrystalline materials have mechanical properties considerably best, than corresponding monocrystals, however, optical properties at polycrystals usually are worse, than at monocrystals because of dispersion and radiation uptake on boundaries of grains [232]. In information IK - systems this phenomenon can be neglected without serious consequences if the working wave length exceeds the medial size of grain. In the laser technics the contribution of additional uptake and dispersion is usually enough important, and consequently use of monocrystals is preferable, but, at excess of some critical size of a detail, manufacturing of optical devices from monocrystals loses sense as the magnification of dimensions of a monocrystal is accompanied by deterioration of its quality at simultaneous sharp growth of specific cost. Among technologists - rostovikov there is an opinion, that problems at cultivation of monocrystals are proportional to a cube of diameter. Therefore for manufacturing of a large-sized crystal optics application of polycrystals, despite the worst optical properties, frequently more
Defensible.

One of expedients of a leaving from expensive technology of cultivation of monocrystals is the method of reception of rather inexpensive large-sized preparations for IK - technicians by hot pressing pure poroshkoobraznyh materials [232, 248]. The optical ceramics made thus is widely used in IK - optics. In СО2 - lasers, basically, can be used serially released ceramic ZnSe and CdTe, known under names irtran-4 (КО-4) and irtran-6 (КО-6), accordingly. In comparison with monocrystals of the same materials, the optical ceramics possesses the raised mechanical strength, is much cheaper in manufacturing, however has essentially bolshy an absorption constant β ~ 0,12÷0,14 sm ' 1. Therefore at a radiation power density from above 100 Вт/см2 in the continuous mode the ceramics cannot be used. The technology of hot pressing poroshkoobraznyh optical materials has started to develop in 50-60 of the last century of. It is possible to guess, that with use nanotehnology, this direction in the XXI-st century will develop even more actively, and optical quality of ceramics will radically be refined, that will allow to apply it and in more powerful lasers. By the way, the technology of reception of laser ceramics for application as the active devices of solid-state lasers [249] is already created. Experiments have shown, that the active devices from laser ceramics have the considerable advantages in comparison, both with monocrystal cores, and with the glass. It was informed on working out in the USA to technology of reception of optical ceramics on the basis of firm solution KCl - KBr by diameter to 1 m for windows powerful CO2 - lasers. It is supposed, that its absorption constant can be up to standard 10 5см ' 1 [250].

Other expedient of reception SHCHGK of optical quality is rather interesting to laser optics with polycrystalline structure - rekristallizatsija vysokochistyh the monocrystals subjected to hot pressing [139, 183, 250 255]. Strength of a material after such thermomechanical processing increases approximately 10 times, but also the absorption constant grows approximately also. The essence of this effect consists that boundaries of grains and some impurities at a room temperature interfere with a motion of dislocations, and optical properties do not worsen almost.

However in the course of storage and operation, in effect, there is long-term otzhig at a room temperature. It causes the appreciable ageing of a material consisting in growth of the sizes of grains in the course of prolonged rekristallizatsii. Plastic strain in polycrystals occurs for the account of migration of boundaries of grains and zernogranichnogo slippages. The motion occurs in a direction of the free surface, that is an optical surface, that naturally leads to deterioration of its shape. Inhibiting action of this process by a doping special impurities [183] is essentially possible.

In the field of 10 microns some non-linear crystals, for example, prustit, ZnGeP2 are transparent also. However application of these crystals is restricted to traditional fields of non-linear optics as they are expensive and possess high uptake, and the technology of their reception is extremely difficult [256].

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A source: Rogalin Vladimir Efimovich. Firmness of materials of power optics to action of powerful impulses of radiation CO2 - lasers. The dissertation on competition of a scientific degree of the doctor of physical and mathematical sciences. Tver - 2015. 2015

More on topic 1.3 Properties of optical materials for field of a spectrum 10 microns. Measure for a select of optical materials of powerful lasers:

  1. 2.5 Optical properties lejkosapfira in the field of 10,6 microns
  2. CHAPTER 6 OPTICAL FIRMNESS OF COPPER MIRRORS FOR POWERFUL PULSING CO2 - LASERS
  3. 3.2 Features of occurrence of plasma formation near to a surface of optical materials and its interrelation with their real optical firmness
  4. 1.4 Optical properties of metal mirrors for CO2 - lasers
  5. 1.3.1 Diamond: optical properties and application prospects in CO2 - lasers
  6. CHAPTER 2 SPEKTROFOTOMETRICHESKY EXAMINATIONS OF OPTICAL MATERIALS
  7. 3.1.1 Experimental technique on examination of a threshold amount of energy of damage of optical materials
  8. CHAPTER 1 OPTICS CO2 - LASERS. PROPERTIES OF USED MATERIALS
  9. 3.3 Morphology of volume and superficial damages of the optical materials resulting action
  10. measuring of an optical gear transmission in IK spectrum fields