The analysis of the roughness of B<SUB>4</SUB>C films of different thickness as well as W/B<SUB>4</SUB>C multilayer mirrors of different periods is performed basing on AFM and x-ray scattering (XRS) measurements. It is demonstrated that the linear model of a film growth is able to describe the whole set of experimental data including films at initial island stage of growth, if suppose the relaxation processes of a film surface to depend on the film thickness. New approach to the inverse problem of x-ray reflectometry consisting in inferring the dielectric constant profile from the reflectivity data is shortly discussed.
High contrast fast switch of transmission in optical channels of iodine laser facilities is supplied with liquid bleachable dye cells. New dye cell designs which combine the functions of an optical shutter and a soft diaphragm are considered. 70 - 100 mm in diameter cell-apodizers of two types (with profiled absorbing liquid layer and profiled transmission of optical components) are developed. Cells with profiled absorbing layer contain meniscus-lens spacer, which cancels the optical power of the device. Cells with plane parallel liquid layer contain windows with profiled transmission. The laser shot-blasted technology for the surface and volume processing of the cell windows was used. For approximately equals 1% initial transmission at the laser beam axis the cells' bleaching reaches 70%, and the contrast ratio of the cells' transmission profile from the beam axis to the periphery may reach K approximately equals 1000. The application of high-aperture cell apodizers in the iodine laser optical channel will make it possible to eliminate the influence on the beam profile of the disturbances in a gaseous active medium at the periphery of amplifier modules caused by the open discharge used for pumping, and to form a smoothed spatial profile of the laser beam.
The potentialities of the x-ray scattering methods (XRS) for quantitative testing of supersmooth surfaces, thin films, and multilayer structures are discussed. The results of the surface roughness study with the use of XRS technique in hard and sort x-ray spectral regions are compared with independent measurements of the roughness by atomic force microscopy (AFM). It is demonstrated that the results obtained by XRS and AFM are in a very good agreement in spite of different physical principles and underlying the methods. XRS technique is applied for the roughness study of thin films which are used in applications for x-ray and UV optics. The XRS method is demonstrated to enable quantitative evaluation of PSD functions of both the film interfaces and the correlation between the substrate and film roughnesses. X-ray investigations of the correlation of the roughnesses of short-period multilayer structures are discussed as well. The use of the whispering gallery effect is demonstrated to extend the XRS method to control of the concave surface roughness.
'Soft' diaphragms have become widely used elements for beam apodization in high-power laser facilities. New types of soft diaphragms are reported. For the diaphragms of the first type a smoothed profile of the transmission coefficient T(r) is formed due to the laser beam energy dissipation on small-scale optical inhomogeneities introduced into the diaphragm aperture, 2r<SUB>0</SUB>. The laser shot-blasted technology for the surface and volume processing of the transparent dielectric plates in order to produce, in plates' apertures, the dissipation regions with the specified transmission profiles is discussed. Soft diaphragms with light diameters of 2r<SUB>0</SUB> equals 10 divided by 100 mm are under development. The damage threshold of the proposed diaphragms is comparable to that of optical glass. Low energy absorption in diaphragms makes them applicable for the pulse-repetitive and cw lasers of different wavelengths. Apodizers of the second type present the cells with a profiled absorbing liquid layers. When using the bleachable dye solutions the diaphragm contrast K equals T(O)/T(r<SUB>0</SUB>) may exceed 10<SUP>3</SUP>. Such cells combine the functions of a passive shutter and a soft diaphragm, and can be used in master oscillator and amplifiers' cascades in high power laser facilities.
Dye cell 'soft' diaphragms for apodization of powerful laser beams are investigated. A cell design with a meniscus lens spacer is proposed to compensate thermal phase distortions in the transmitted laser beam. laser shot-blasted 'soft' aperture technology is discussed. The obtained results have revealed a feasibility to create a wide-aperture nonlinear optical decoupling element - apodizer for application in powerful iodine, neodymium and excimer lasers.