High Power, High Repetition Rate, Pulsed, Blue Laser for ASW Purposes

A laser will be developed which meets the Navy requirements for airborne anti-submarine warfare missions. These requirements include high repetition rate, short pulse operation at blue wavelengths, and a compact, robust package. The laser will be based on a wavelength shifted, diode pumped alexandrite laser. The wavelength shifting is accomplished by means of Raman and second harmonic conversion. Data are presented for diode pumped alexandrite lasers and Raman conversion from low repetition rate flashlamp pumped alexandrite lasers operating at the required energies. This work builds on Light Age’s demonstrated technologies including its Raman convertors which can handle the 100W power levels required. Phase I will provide studies of the scaling required for diode pumping and a laboratory demonstration of efficient conversion of flashlamp pumped alexandrite output at 753 nm to 486 nm. Phase I goals are the demonstration of the power requirements and efficiency for the conversion of 753 nm light to 486 nm and a design for scaling the diode pumped alexandrite lasers to provide the requisite power. In the Phase II, a prototype system will be demonstrated at 486 nm, with 10 mJ pulse energy at 1000 Hz repetition rate and sub-20-nsec pulsewidth.