Widely-tunable mid-IR frequency comb source based on difference frequency generation

Abstract

We report on a mid-infrared frequency comb source of unprecedented tunability covering the entire 3-10 μm molecular fingerprint region. The system is based on difference frequency generation in a GaSe crystal pumped by a 151 MHz Yb:fiber frequency comb. The process was seeded with Raman shifted solitons generated in a highly nonlinear suspended-core fiber with the same source. Average powers up to 1.5 mW were achieved at 4.7 μm wavelength.

3 pages, 3 figures