Highly coherent tunable mid-infrared frequency comb pumped by supercontinuum at 1 mu m

摘要

We report a tunable mid-infrared frequency comb working at 184 MHz, which is based on difference frequency generation in a periodically poled Mg-doped stoichiometric lithium tantalate (PPMgSLT) crystal pumped by high-power supercontinuum pulses. Supercontinuum pulses from two fibers with different dispersion properties were examined. With a photonic crystal fiber (PCF) having normal dispersion properties, a tunable wavelength range of 2.9-4.7 mu m was achieved. With another PCF having zero dispersion at 1040 nm, a maximum power of 1.34mW was observed at 3.9 mu m. The high coherence of the pulses generated with this scheme was verified experimentally, and a fringe visibility of 0.90 was observed. (C) 2017 The Japan Society of Applied Physics