Second harmonic generation in transparent microcrystalline α-CdGa2S4-containing chalcogenide glass ceramics

Transparent glass ceramics were prepared by heat treating of the as-prepared 80GeS2 · 10Ga2S3 · 10CdI2 glass at 370 °C (Tg + 15 °C) for 72 h (labeled as GGCd10-370). The existence of α-CdGa2S4 crystal in GGCd10-370 glass ceramics has been testified by XRD and Raman spectroscopy. Using the typical Maker fringe technique, SHG was observed in the original transparent GGCd10-370 glass ceramics successfully, which is mainly ascribed to the α-CdGa2S4 nonlinear optical microcrystal. And the SH intensity is almost 0.8 times larger than that of the standard quartz reference. It can be also deduced that the thickness of crystalline layer is a little larger than the coherent length, lc ≈ 2.7 μm.