Stabilized 2051 nm TmHo:YLF laser and applications in Barium 137*

We report on the development of a tunable frequency stabilized laser operating at a wavelength of 2051 nm and its applications in $^{137}$Ba$^{+}$. A commercially available TmHo: YLF laser was frequency doubled using a periodically poled lithium niobate crystal and then frequency shifted using a broadband acousto-optic modulator. The shifted 1025 nm beam was then sent into a reference cavity with a finesse of approximately 350,000 made of ultra-low expansion glass, and the laser frequency is stabilized using the Pound-Drever-Hall method. Using a linear Paul trap, we confine and laser cool single barium ions, and excite the 6S$_{3/2}$ to 5D$_{3/2}$ clock transition at 2051 nm. We plan to use this electric quadrupole transition as a clock transition in an optical frequency standard. This TmHo: YLF laser will also be employed to perform precision spectroscopy of the 5D$_{3/2}$ manifold which will allow us to determine the nuclear magnetic octopole moment of $^{137}$Ba. Finally, we have plans to use this laser to test atomic parity non-conservation in a single trapped $^{137}$Ba ion.