High-power solid state lasers operating beyond 1300-nm have been proposed as eye-safer 0x9D sources in military applications such as LADAR and directed energy weapons. Erbium-doped solid state lasers provide an attractive gain medium due to emission at eyesafe wavelengths , and the potential for low and ultra-low quantum defect pumping by diode lasers operating around 1470-nm and 1532-nm, respectively . As a result, there is currently great interest in the further development of high-power, high-efficiency diode lasers at these wavelengths to better enable efficient (direct) pumping of such laser systems. Under the proposed Phase 1 program, nLight will design, grow, fabricate, test, and deliver to the Navy (or a recipient of their choosing) a 50W (rated, 25 C) compact, conductively-cooled diode laser pump module, coupled to a 200 m core, 0.22 NA fiber. The unit will emit at 1532 nm with a linewidth of 0.3 nm FWHM with an electrical-to-optical efficiency (measured at the fiber output) of 35%. As an option to the program, nLight will conduct a second iteration of design, growth, and fabrication to target improved temperature performance.
Benefit: In the military sector, due to the possibility of unintended collateral eye damage, eyesafe laser transmitters will find applications in virtually all applications which are currently served by non-eyesafe solutions. Such applications include target designation, rangefinding, 3D imaging and surveillance, autonomous vehicles, directed energy, and the Multi-Mode Sensor/Seeker (MMSS) system. nLight is a leading supplier of laser components to the defense community. In the commercial sector, the applications for compact, eyesafe LADAR transmitters include 3D mapping, autonomous vehicle parking, adaptive cruise control, remote sensing, and a direct-diode medical. The pump diodes to be developed under this program will ultimately lead to smaller, less complex, more reliable laser systems suitable for many, if not all, of these applications. nLight has a good track record of commercializing the results of DoD-funded research, and expects to commercialize the results and devices produced under this program as rapidly as possible.
Keywords: Er:YAG lasers, Er:YAG lasers, wavelength stabilization, eye-safe lasers, InP diode lasers, volume Bragg grating, fiber-coupled diode lasers
