Freedom Photonics LLC SBIR Phase II Award, July 2021

Freedom Photonics proposes the development of watt-class diffraction-limited diode lasers with extremely high reliability for pumping solid state lasers.nbsp; Two target operating wavelengths will be pursued, 808 nm and 885 nm, in order to support the two common pump bands for Nd:YAG microchip lasers.nbsp; Diffraction-limited pump diodes enable close matching of the end-pumped gain region to the fundamental cavity mode of the solid state laser.nbsp; This approach improves the laser efficiency, power, beam quality, and reliability, all of which are critical for space-based LIDAR systems.nbsp; In Phase 1, Freedom Photonics demonstrated 885 nm diffraction-limited lasers with gt;1.8 W output power and excellent robustness.nbsp; These results were enabled by laser epitaxial designs with extremely high efficiency and facets robust to catastrophic optical mirror damage by means of advanced passivation technology.nbsp; In Phase 2,nbsp; the operating power and efficiency will be further improved, and these diffraction-limited pump lasers will also be scaled to an emission wavelength of 808 nm.nbsp; Reliability and environmental testing will be carried out to demonstrate compatibility with space flight operation.nbsp; nbsp;nbsp;Spectral narrowing and wavelength stabilization will allow for maximum pump absorption without the need for strict control of the diode junction temperature.nbsp;