The development of an all-solid-state systems of lasers is described for the cooling and probing of strontium ions in a radio-frequency (rf) trap. The Sr⁺ ions created within the rf trap are laser cooled by repeated cycling on the 422 nm ²S_1/2 - ²P_1/2 resonance transition. The 422 nm light was generated from a single mode 70 mW 844 nm diode laser, whose output was frequency doubled to 422 nm in a KNbO₃ crystal inside a resonant enhancement cavity. Decays from the Sr⁺ upper resonance level into the ²D_3/2 metastable state remove ions from the cooling cycle. This loss was prevented by driving the 1092 nm ²D_3/2 - ²P_1/2 transition using a Nd³⁺-doped fiber laser, diode-pumped at 826 nm. The ²S_1/2 - ²D_5/2 optical 'clock' transition at 674 nm has a natural linewidth of 0.4 Hz and may be probed with an AlGaInP laser diode. The laser diodes at 844 nm and 674 nm are both collimated using a piezo-mounted GRIN rod which also provides longitudinal mode selection. The spectral output is optically narrowed using resonant optical feedback.

Date Published: 30 April 1993
PDF: 7 pages
Proc. SPIE 1837, Frequency-Stabilized Lasers and Their Applications, (30 April 1993); doi: 10.1117/12.143700

Published in SPIE Proceedings Vol. 1837:
Frequency-Stabilized Lasers and Their Applications
Y. C. Chung, Editor(s)