Abstract

Precision spectroscopy of single trapped Barium ions requires a narrowband, drift-free light source at 493 nm. We have built a frequency doubled diode laser which produces 60 mW of light at 493 nm with a spectral bandwidth of less than 30 kHz. The system consists of a 986 nm diode laser in a Littmann cavity configuration, Pound-Drever-stabilized to a reference cavity, and an external doubling resonator with a KNbO₃ crystal, Pound-Drever-stabilized to the frequency of the 986 nm light. We employ an SDL laser diode with 150 mW maximum output power, a 4-mirror doubling resonator in ring geometry, and 80 dB isolation between the laser cavity and the doubling resonator. We achieve a conversion of 94 mW before the doubler into 60 mW frequency doubled light, corresponding to an efficiency of 63%.

© 1998 IEEE