Optical frequency standard development in support of NASA's gravity-mapping missions

We. have begun constructing all-solid-state laser systems at 778 nm and at 532 nm in support of a satellite-based gravity-mapping mission tentatively planned to fly in 2007. In each case the lasers will be stabilized at short times to high-finesse Fabry-Perot cavities. At longer times the 778 nm laser will be stabilized to the 2-photon transition in rubidium.. In the 532 nm system, a frequency-doubled Nd:YAG laser with a non-planar ring oscillator (NPRO) design will be frequency-locked to a molecular iodine line. We intend to combine the exquisite performance over short time scales coming from a cavity reference with the long-term stability of an atomic frequency standard with an eye towards reliability in a spaceflight. application. By developing. two separate candidate systems with proven performance we intend to maximize the probability of success for this mission-critical system development.