Abstract

A single ¹⁹⁹Hg⁺ion is confined in a miniature rf trap and is laser cooled. We have performed spectroscopic measurements of the 5d¹⁰6s ²S_1/2↔⁵d⁹6s^{2 2}D_5/2 electric quadrupole transition near 282 nm and obtained a linewidth of ~80 Hz (FWHM). The natural linewidth for this transition is 1.8 Hz (as determined from the measured lifetime¹), which makes it an attractive candidate as an optical frequency standard. Our measurements are currently limited by the laser linewidth at 282 nm. Optical heterodyne measurements of two independently stabilized beams gives us direct information of the noise spectrum and its amplitude.

© 1990 Optical Society of America