Abstract

We have investigated mid-infrared generation using cascaded optical parametric oscillators pumped by a Q-switched, 1047 nm Nd:YLF laser at pulse repetition rates of several kilohertz. Cascading two OPOs with different nonlinear crystals provides opportunities for optimizing operating parameters that are more restricted in direct laser pumping of a single OPO. Non-critically phase matched (NCPM) AgGaSe₂ OPO pumped by another OPO with pump wavelengths near 1.5 μm is an example of this approach. The NCPM AgGaSe₂ crystal generates broadly tunable output by tuning the pump wavelength. The pump wavelengths canbe chosen to avoid absorption bands, thereby reducing thermal loading effects. These features are important for devices that operate at high pulse repetition rates (>kHz) and average powers greater than 1 W.

© 1995 Optical Society of America