A low-temperature external cavity diode laser for broad wavelength tuning

We report on the design and characterization of a low-temperature externalcavitydiode laser (ECDL) system for broad wavelength tuning. The performance achieved with multiplediode models addresses the scarcity of commercial redlaser diodes below 633 nm, which is a wavelength range relevant to the spectroscopy of many molecules and ions. Using a combination of multiple-stage thermoelectric cooling andwater cooling, the operatingtemperature of alaser diode is lowered to −64 °C, more than 85 °C below the ambienttemperature. The laser system integratestemperature anddiffraction grating feedback tunability for coarse and fine wavelength adjustments, respectively. For two differentdiode models, single-mode operation is achieved with 38 mW output power at 616.8 nm and 69 mW at 622.6 nm, more than 15 nm below their ambienttemperature free-running wavelengths. The ECDL design can be used fordiodes of any available wavelength, allowing individualdiodes to be tuned continuously over tens of nanometers and extending the wavelength coverage of commerciallaser diodes.

Source: Review of Scientific Instruments - November 10, 2016 Category: Physics Authors: William G. Tobias, Jason S. Rosenberg, Nicholas R. Hutzler and Kang-Kuen Ni Source Type: research