High Power Blue-Green Laser Sources

In this proposed Phase I program, we will study methods of generating blue-green laser radiation. Such sources are of great interest to the Navy for both anti-submarine warfare and communications at depth and speed, as blue-green light matches the minimum of seawater transmission for a variety of conditions. In addition, there are military applications in pumping Ti:Sapphire lasers for stable clocks as well as applications for bioinstrumentation, displays, and fundamental research. We propose to study methods of generating blue-green radiation by either fiber-laser or crystalline solid-state laser sources. In both cases, several frequency conversion steps may be required. For fiber-laser-based sources, we propose to investigate Raman oscillators to shift the fiber sources to the red and nonlinear frequency conversion (second, third, and fourth harmonic generation) to convert wavelengths into the blue-green range. For solid-state lasers, optical parametric oscillators will be investigated to generate tunable blue-green wavelengths. An optimal combination of frequency conversion will be sought that maximizes both efficiency and power scalability, among other properties. Maturity and availability of the technology will be considered in choosing amongst the candidate technologies. The result of the Phase I program will be to identify the best path to an efficient multi-Watt blue-green source.