The first demonstration, to the best of our knowledge, of continuous-wave (cw) difference-frequency generation (DFG) in LiInS2 crystal is reported. Wide spectral coverage (5.5-11.3 μm) has been obtained with angle and wavelength tuning for type II (eoe) critically phase-matched parametric interaction. The phase-matching conditions in cw DFG have been investigated, which allowed us to improve the Sellmeier parameters by use of a two-pole dispersion equation. An effective nonlinear coefficient deff = 6.9 ± 0.8 pm/V has been determined at ∼7 μm relative to the well-known nonlinear coefficient d36 of AgGaS2, which yields a power-conversion efficiency of ∼12.4 μW/(W2 cm). We evaluated the high-resolution spectral characteristics of the DFG source by recording C2H2 and SO2 spectra.
ASJC Scopus subject areas
- Atomic and Molecular Physics, and Optics
- Engineering (miscellaneous)
- Electrical and Electronic Engineering