Third and second order non linear optical properties of Ge-Se-S-As chalcogenide glasses

摘要

Chalcogenide glasses in the [Ge-Se-S-As] system have been synthesized and studied with respect to their non linear optical properties from third and second order. Z-scan and Mach Zehnder interferometry measurements of the non linear refractive index (n_2) and non linear absorption (β) have been performed at 1064 run. Some z-scan measurements have been also realized at 1430 nm. The results have been correlated to the structures of the glasses and the figure of merit has been calculated with the purpose of a potential utilization of these glasses in the realization of ultra-fast all-optical switches. Non linearities as high as 850 times the non linearity of silica glass have been obtained and some glasses exhibit at 1430 nm non linear optical characteristics suitable for telecommunication applications. The all-optical poling of a chalcohalogenide glass has been realized with a Q-switch mode-locked Nd:YAG laser at 1064 nm emitting 45ps pulses at a repetition rate of 10 Hz with frequency doubling at 532 nm. A non linear coefficient d_(eff)= 2.8 10~(-17) m/V similar to that of the reference glass Schott SF 57 has been obtained. The thermal poling of a chalcogenide glass has been also realized and a transient second order non linear susceptibility x~((2)) has been observed.