A Broadly Tunable Ultrashort Pulse IR OPO Pumped by a Mode-Locked

We propose to develop an innovative, compact ultrafast high brightness laser source, broadly tunable in the infrared for vibrationally-resolved infrared microscopy and other applications. By passive Kerr lens mode-locking of a novel diode-pumped tunable Cr:LiSAF laser, 100fs pulses will be generated at 100 MHZ repetition rate with an average power of 1W. An optical parametric oscillator (OPO) pumped with this ultrafast laser generates rapidly tunable infrared output. By taking advantage of new quasi-phase matched nonlinear materials, the OPO will achieve frequency conversion over the 1 to 5m range with efficiencies greater than 30%. Several features that make our proposed laser uniquely suitable for this application are: the pump tuning method provides tunability over a broad range otherwise unattainable, wide operating bandwidths (800cm-1); excellent beam quality and high efficiency; potential use as an efficient primary source for extension to 10m and potential for even shorter pulses (40fs). In Phase 1, after a detailed analysis, a bread-board diode-pumped short pulse Cr:LiSAF laser will be built and used to pump an OPO. These experiments will provide data for comprehensive design of the Phase 2 laser. In Phase 2 a prototype tunable mode-locked laser and OPO will be fabricated and tested.