Mid-IR frequency comb source spanning 44–54 μm based on subharmonic GaAs optical parametric oscillator

Abstract

Broadband mid-IR output suitable for producing 1000-nm-wide frequency combs centered at 4.9 $μ$m was achieved in a degenerate subharmonic optical parametric oscillator (OPO) based on 500-$μ$m-long Brewster-angled orientation-patterned GaAs crystal. The OPO was synchronously pumped at 182 MHz repetition rate by 100 fs pulses from a Cr2$+$:ZnSe laser with the central wavelength of 2.45 $μ$m and the average power of 100 mW.