/sup 199/Hg/sup +/ optical frequency standard: progress report

We are developing an optical frequency standard based on the narrow /sup 2/S/sub 1/2/-/sup 2/D/sub 5/2/ electric-quadrupole transition of a single trapped /sup 199/Hg/sup +/ ion. Small linear traps designed to operate at liquid helium temperatures have been constructed which will provide confinement in the Lamb-Dicke regime for the optical transition. Cryogenic operation yields long ion storage times and significantly suppresses frequency shifts due to collisions and blackbody radiation. A major step toward the completion of this standard has been the construction and evaluation of a well isolated, high-finesse, Fabry-Perot cavity to stabilize the frequency of the interrogating laser. We report our cavity results and progress toward locking the laser frequency to the transition in the stored ion.