Sub-systems for optical frequency measurements: application to the 282-nm Hg-199(+) transition and the 657-nm Ca line

We are developing laser frequency measurement technologies that should allo w us to construct an optical frequency synthesis system capable of measurin g optical frequencies with a precision limited by the atomic frequency stan dards. The system will be used to interconnect and compare new advanced opt ical-frequency references (such as Ca, Hg+, and others) and eventually to c onnect these references to the Cs primary frequency standard. The approach we are taking is to subdivide optical frequency intervals into smaller and smaller pieces until we are able to use standard electronic-frequency-measu rement technology to measure the smallest interval.