Novel Wavelength Standards in the Near IR

The goal of this work is to develop a new class of portable optical frequency references based on sub-Doppler spectroscopy inside gas- filled hollow-core photonic bandgap optical fiber. This research has three major components, consisting of spectroscopy in hollow fiber, the development of a near-IR optical frequency comb with which to characterize the transitions inside the fiber, and efforts to seal these fibers filled with molecular gases to create portable frequency references. Sub-Doppler spectra were observed for the first time in such fibers, and the dependence of the feature width on fiber core diameter was established. A mode-locked chromium-doped forsterite laser based on prism pair dispersion compensation was stabilized as an optical frequency comb for the first time, and unique noise properties were identified. Dramatic narrowing of the carrier-envelope offset frequency fsub0 was observed when a knife-edge was inserted in the optical cavity. Finally, new fusion splicing techniques for hollow-core photonic bandgap optical fiber were developed.