Phase-matched second-harmonic generation is obtained in various LiInS2 crystals by use of the tunable picosecond output of the free-electron laser for infrared experiments (FELIX) as the pump source in the mid-IR range from 2.75 to 6.0 μm. Deviations from the phase-matching curve calculated from Boyd's refractive-index data are observed. Furthermore, the optical damage threshold of the crystals has been measured to be 1.1. J/cm2 (>6 GW/cm2) at the 5-μm wavelength. LiInS2 holds great promise for parametric interaction in the 1-13-μm range.
ASJC Scopus subject areas
- Atomic and Molecular Physics, and Optics