Results have shown that CW optical parametric oscillators (OPOs) can produce high power at 3.5 micron, but have problems going to longer wavelengths. Synchronously-pumped mode-locked OPOs pumped by diode-pumped solid-state lasers are emerging as solutions to the CW problems at the longer IR range. The key to obtaining longer wavelengths is short pulses, which allow shorter lengths of periodically poled lithium niobate (PPLN) to be used since PPLN is absorptive beyond 4.3 micron. To pump the synch-pumped OPO, we propose to build a low-power (air-cooled), short-pulse source based on a mode-locked master oscillator-power amplifier (MOPA) laser. We will then amplify the master oscillator with a new fiber amplification approach that has recently come available from great advancements in the fiber optic technology. There are many advantages of the fiber amplifier including it's straight forward design. Although, the main risk to consider with this fiber amplification approach is driving the fiber with too much signal peak power. The nonlinear problems associated with having too much peak power could be solved by increasing the core size of the fiber relative to the cladding size. This would help because not only will the intensity decrease, but the absorption per unit length will increase.Anticipated Benefits/Commercial Applications: One particulary valuable application of synchronously-pumped mode-locked OPOs pumped by master oscillator-power amplifiers for the military is in high-power laser systems used for IR countermeasures (IRCM). Other applications in the commerical sector include remote sensing, spectroscopy, medical instruments, and laser display systems. Laser display systems require ~10 W per color (red/green/blue). The market for laser sources for projection displays is estimated to be 5,000 units per year starting in a few years. This is a huge business by the current standards of the solid-state laser industry.
