Compositionally tuned lasers for remote sensing

NASA needs lasers that are capable of generating a specific preselected wavelength, have a small but useful tuning range, and are highly efficient. NASA Langley responded to this need by developing 2 compositionally tuned Nd laser materials that operate at a preselected wavelength, 0.94411 μm in this case. Although Nd:YAG was known to operate at 0.946 pm, it could not be tuned to 0.944 μm. In addition, the efficiency of Nd:YAG flash lamp pumped lasers operating at this wavelength was low. NASA Langley overcame these problems by analyzing and then utilizing nonstoichiometric garnet laser materials to compositionally tune the laser wavelength and a laser design to increase the efficiency. Implementing these ideas led to 2 compositionally tuned laser materials that operate at 0.94411 μm and a diode pumped, 0.946 μm Nd:YAG laser that operates in the TEM 00 mode with a normal mode, optical to optical slope efficiency of 0.28.