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We present what we believe to be a novel technique to minimize UV-induced damage in experiments that employ second-harmonic generation cavities. The principle of our approach is to reduce the duty cycle of the UV light as much as possible to prolong the lifetime of the used optics. The low duty cycle is achieved by ramping the cavity into resonance for a short time during the experimental cycle when the light is used and tuning it to an off-resonant state otherwise. The necessary fast ramp and length-stabilization control of the cavity is implemented with the FPGA-based STEMlab platform. We demonstrate the utility of this method by measuring the isotope shift of the electronic transition (X1Σ ← A1Π) in AlCl at 261.5 nm in a pulsed molecular beam experiment.
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Stable 2 W continuous-wave 261.5 nm laser for cooling and trapping aluminum monochloride
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 theA1Π ← X1Σ+transition in a cold, slow beam of AlCl molecules and probe the A1Π|v′ = 0,J′ = 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.
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- Award ID(s):
- 1848435
- PAR ID:
- 10304152
- Publisher / Repository:
- Optical Society of America
- Date Published:
- Journal Name:
- Optics Express
- Volume:
- 29
- Issue:
- 23
- ISSN:
- 1094-4087; OPEXFF
- Format(s):
- Medium: X Size: Article No. 37140
- Size(s):
- Article No. 37140
- Sponsoring Org:
- National Science Foundation
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