Mid-Infrared OPO Pumped by a Tunable Diode Pumped Solid State Laser

The main objective of this proposal is to design and develop an all-solid-state, high repetition rate laser source, tunable throughout the 1.5 to 3.5 um wavelength range. The proposed source will have a peak power greater than 1 kW at multi-kHz repetition rate. It will be based upon an optical parametric oscillator (OPO), and provides the wide tuning range by utilizing a pump source which is also widely tunable - a diode-pumped Cr:LiSAF laser. This unique device utilizes an OPO with a low threshold that allows use of diode-pumped laser. Specific aims of the Phase I effort include an investigation of a range of newly available efficient Arsenate nonlinear optical materials, KTA, CTA and RTA that have transmission out to 5 um. Experiments will be performed using a high pulse energy tunable pump laser, to demonstrate OPO oscillation in these crystals, and to establish their threshold pump energy requirement. We will also demonstrate the broad tunability achieved by using a tunable pump source. Finally, the design of phase II high pulse energy (2-3mJ), tunable (780-1000nm) Cr:LiSAF pump laser will be carried out. In phase II the miniature mid-IR OPO pumped by the diode-pumped tunable laser will be fabricated and tested.