Studies of optical non-linearities of chalcogenide and heavy-metal oxide glasses

We present measurements of third order optical non-linearities in heavy-met al oxide and sulfide glasses, using the z-scan, time-resolved z-scan, and s pectrally resolved two-beam coupling techniques. The non-linear index of re fraction is found to increase with heavy-metal and sulfide content, and the nuclear contribution to the non-linearity is found to be approximately con stant at (15 +/- 3)%. The largest non-resonant non-linear index of refracti on occurs in 35La(2)S(3). 65Ga(2)S(3). It is 30 times larger than the non-l inear index of refraction in fused silica. (C) 1999 Elsevier Science B.V. A ll rights reserved.