Difference-frequency generation by mixing dual-wavelength pulses emitting from an electronically tuned Ti : sapphire laser

Broadly tunable difference-frequency generation (DFG) in AgGaS2 was achieve d by mixing dual-wavelength oscillating pulses from an electronically tuned Ti:sapphire laser with a two-frequency-driven acousto-optic device. Contin uous tuning from 6.5 to 8.5 mu m was achieved by simultaneous dual-waveleng th-tuned DFG without crystal rotation. In the dual-pulse oscillation, the s horter and longer wavelength pulses were tuned from 700 to 775 nm and from 763 to 880 nm, respectively, while keeping the phase-matching relationship for DFG. When crystal rotation was adopted, however, the tunable output ran ge was extended from 5.3 to 12 mu m by tuning the longer wavelength pump pu lse, while the shorter wavelength pulse was fixed.