The Optically Pumped Semiconductor Laser (OPSL) offers several advantages as a laser source for precision spectroscopy. The semiconductor gain bandwidth allows an OPSL to run continuous wave (CW) between 920 - 1154 nm and with a free running linewidth 500 kHz. High powers have been observed in OPSL, as high as 70 W. Paired with doubling crystals the wavelength range can be extended down to the ultraviolet(UV) with high power. This research presents an OPSL operating at 972 nm at 1.7 W sequentially doubled down twice to a wavelength of 243 nm at 150 mW. The linewidth is reduced by locking one OPSL to a Fabry-Poret stabilization cavity and then the relative linewidth was measured between two OPSL's locked together. The linewidth is determined to be 87 kHz, dominated mostly by technical noise. This laser is set to be used for cryogenic hydrogen spectroscopy and precision measurements of the Lamor precessional frequency of ¹²⁹Xe when it is used as a comagnetometer for measuring the electrical dipole moment (EDM) of the neutron.Science, Faculty ofPhysics and Astronomy, Department ofGraduat
