Optical and dc-electric treatment of GeS₂-Ga₂S₃-AgCl chalcohalide glasses

I.V.Kityk, K.Ozga

Poland

M.Frumar, C.Wagner

Czech Republic

 

Materials with large second-order optical nonlinearity (SON) have attained a variety of applications, e.g. frequency conversion, high density storage, photonic modulator, etc. By certain treatments say, optical poling (OP), thermal-electrical poling or electron beam irradiation (EBI), glasses can also acquire SON due to breaking down of inversion symmetry. Taking into account the low-cost and easy fabrication of glasses as compared to expensive nonlinear crystals, it is necessary to find glasses of high SON. Chalcogenide and chalcohalide glasses, due to much larger third-order optical nonlinearity (TON) than oxide glasses, have been drawing on extensive studies. Here we study influence of polarized optical treatment by 10 ns Nd-YAG lasers at wavelength 1320 nm together with electrostatic dc electric field on the output second harmonic generation. We use the same laser beam for optical treatment and for the probing. We will study an influence of the addition of the Ag ions on the output second harmonic generation. For the first time we have discovered substantial second order susceptibilities of the 60GeS2-20Ga2S3-20AgI(Br) glasses. We have found that maximal second order susceptibility was achieved after the 1 min, of electrical-optical treatment for the following parameters: electric field strength - 8 kV/cm and optical power density about 6 GW/cm². The further increase of these two parameters has led to a decrease in the output second order susceptibilities. Absence of simultaneous treatment (optical or electrical field one) does not allow the output second order susceptibility to be obtained with a value larger than 0.4 pm/V, which at the precision of about 0.1 pm/V is a relatively low value. After switching off one component of the field (the optical or the electrical) the output second order susceptibilities decrease during several seconds up to 0.3-0.5 pm/V.