Interferometric frequency measurement of aTe2130reference line for muonium1S−2Sspectroscopy

Abstract

We report on an interferometric frequency measurement of a ${}_{}{}^{130}{}_{}{}^{}\mathrm{Te}_2^{}{}_{}{}^{}$ absorption line which can be used as a reference in Doppler-free two-photon spectroscopy of the muonium $1S-2S$ transition. The frequency of this 488-nm ${}_{}{}^{130}{}_{}{}^{}\mathrm{Te}_2^{}{}_{}{}^{}$ transition is determined with a precision of 1 part in ${10}^9$ by comparison with a previously calibrated ${}_{}{}^{130}{}_{}{}^{}\mathrm{Te}_2^{}{}_{}{}^{}$ line near 486 nm.