Progress toward an Optical Frequency Standard using ^199Hg^+ Ions
Abstract
Although the stability and accuracy of microwave frequency standards have improved substantially, perhaps the best avenue for higher performance lies in the development of optical frequency standards. Because optical frequencies are about 10^5 times higher than the 9.2 GHz microwave transition used in cesium standards, much higher fractional stability might be achieved in a given measurement time. We are developing an optical frequency standard based on a 1.7 Hz-linewidth quadrupole transition of ^199Hg^+ ions at 282 nm. We lock light from a dye laser to an isolated and stable high-finesse Fabry-Perot cavity to create an optical frequency source at 563 nm with good short-term stability, which will eventually be frequency doubled and locked to the Hg^+ transition to achieve long-term stability. Recent improvements in the laser system have narrowed the linewidth from earlier results(J.C. Bergquist, W.M. Itano, and D.J. Wineland, ``Laser Stabilization to a Single Ion,'' in Frontiers in Laser Spectroscopy), pp. 357--76, 1994. of about 20 Hz to roughly 6 Hz. Additionally, we are developing solid state laser replacements for the gas and dye lasers that drive 194 nm and 282 nm ^199Hg^+ transitions.
- Publication:
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APS Division of Atomic, Molecular and Optical Physics Meeting Abstracts
- Pub Date:
- May 1998
- Bibcode:
- 1998APS..DMP..I609Y