Advances in ultrafast optical parametric sources for the mid-infrared based on CdSiP_2

Abstract

We describe the evolution of ultrafast optical parametric sources for the mid-infrared (mid-IR) based on the new birefringent nonlinear crystal, cadmium silicon phosphide, CdSiP2, using well-established Nd-based solid-state and Yb-based fiber pump lasers near 1 μm. Optical parametric generators and optical parametric oscillators (OPOs) providing high-energy picosecond pulses, as well as high-repetition-rate femtosecond pulses, at high average powers across the 6–7 μm spectral range in the mid-IR are described in detail. Studies of viable pump laser technologies suitable for ultrafast femtosecond OPOs based on CdSiP2 are discussed, and the favorable linear and nonlinear optical properties, as well as unique phase-matching characteristics of CdSiP2, are presented using the most recent Sellmeier equations for the material. The described experimental results represent the highest output pulse energy and record average power in the ultrafast picosecond and femtosecond time scales across the 6–7 μm spectral range to date.