A stable 2 W continuous-wave 261.5 nm laser for cooling and trapping aluminum monochloride

Abstract

We present a high-power tunable deep-ultraviolet (DUV) laser that uses two consecutive cavity enhanced doubling stages with LBO and CLBO crystals to produce the fourth harmonic of an amplified homebuilt external cavity diode laser. The system generates up to 2.75 W of 261.5 nm laser light with a ~2 W stable steady-state output power and performs second harmonic generation in a largely unexplored high intensity regime in CLBO for continuous wave DUV light. We use this laser to perform fluorescence spectroscopy on the $X^1\Sigma \leftarrow A^1\Pi$ transition in a cold, slow beam of AlCl molecules and probe the $A^1\Pi |v^{\prime }=0,J^{\prime }=1>$ state hyperfine structure for future laser cooling and trapping experiments. This work demonstrates that the production of tunable, watt-level DUV lasers is becoming routine for a variety of wavelength-specific applications in atomic, molecular and optical physics.

10 pages, 4 figures

References in corpus (6)

• Laser cooled molecules
• Optical cycling of AlF molecules
• Spectroscopy on the $A^1\Pi \leftarrow X^1{\Sigma }^{+}$ Transition of Buffer-Gas Cooled AlCl
• Single-photon cesium Rydberg excitation spectroscopy using 318.6-nm UV laser and room-temperature vapor cell
• Stable High Power deep-UV Enhancement Cavity in Ultra High Vacuum with Fluoride Coatings
• Yb fiber amplifier at 972.5 nm with frequency quadrupling to 243.1 nm