Yu.M.Andreev, P.P.Geiko, L.G.Geiko, S.G.Grechin
"Phase matching and optical properties of LiInS2 nonlinear crystal"
Proceedings of SPIE, 2002, v.4747, p.399-404
Results on investigation of linear and non-linear optical properties, damage threshold and potential efficiencies of biaxial LiInS2 crystal are represented. Transmission range is 0.4-12.5 um at the 0.1 level and 0.5-11.0 um at the 0.5 level. Typical absorption coefficients are as low as 0,1-0,25 cm-1 at the maximum transmission range 1.0-8.0 um and 1.1-2.3 cm-1 at the CO2 laser wavelengths.
Coefficients of second order non-linear susceptibilities are d31=6.2, d32=5.4 and d33=9.8 pm/V, but damage threshold is as high as 120-130 MW/cm2 for 36 ns pulses at 9.55 um. The phase-matching is estimated with using of determined Sellmeier coefficients. It is represented in graphic form so as fields of SHG efficiencies. It is shown that LiInS2 can be used in middle IR OPO pumped by Cu-vapor laser, group-velocity phase matching take place in wide spectral
range for sum- and difference-frequency generation of visible, near and middle IR lasers including SHG of 3 um Er laser.