Electro-optic glasses and glass ceramics for elements controlling laser radiation

The results of studying the electro-optical sensitivity of industrial glasses are presented, and it is shown that Kerr constant, B, of them does not exceed 10 -15 m/V 2 . An approach to the choice of compositions of the glasses of high Kerr sensitivity is developed, and experimental sodium- niobium-silicate glasses with B > 10 -14 m/V 2 have been designed and formed. The approach is based on the hypothesis of 'crystalline motifs' (structural inhomogenities responsible for electro-optical sensitivity of the glasses), which are the ordered regions (several coordination spheres) with the crystal-like structure. When heat-treated the designed glasses crystallize, with the phase precipitated being NaNbO 3 microcrystals. Temporal-thermal conditions of the glass crystallization to form a transparent glass-ceramics with B approximately equal 10 -12 m/V 2 have been found. It has been also shown that such glass-ceramics can be produced by high-temperature alkaline ion exchange. A low- temperature silver ion exchange in the designed glasses and glass-ceramics has been studied and optical waveguides supporting from 1 to 50 modes have been formed. In these waveguides the index variation equal to 0.15 is achieved.