Generation of tunable infrared picosecond pulses at 100 MHz by difference-frequency mixing in KTiOPO(4)

Picosecond pulses, tunable in the wavelength range of 1.2-4.5 microm, are generated at a 100-MHz repetition rate in KTiOPO(4) by difference-frequency mixing the output of a synchronously mode-locked dye laser and a Nd:YLF laser that pumps the dye laser. The typical average infrared output power is in the milliwatt range, which represents an improvement of several orders of magnitude over previously reported results using other nonlinear materials in a similar setup with Nd:YAG as the driving source. The high average power of this infrared source and its broad tunability make it an attractive alternative for mode-locked color-center lasers.