High Power Volume Bragg Laser Bar with 10 GHz spectral bandwidth

摘要

Diode pumped alkali-vapor (cesium, rubidium and potassium) lasers (DPALs) are attractive sources for high-power applications due to their high quantum efficiency, excellent optical beam quality and reduced thermal load. DPALs require optical pump sources that can reliably emit energy within the narrow (about 10 GHz) absorption bands of the alkali vapor. Single laser diodes (LD) and laser bars (LB) integrated into wavelength selective external cavities with volume diffraction gratings can simultaneously achieve narrow linewidths and high output power. A diode laser bar with a volume Bragg grating output coupler emitting at 780 nm has demonstrated a CW output power up to 30 W with a slope efficiency of 0.8 W/A, a spectral width (FWHM) below 10GHz, and a tunability over 400 pm. The output power of a diode bar in an external cavity exceeded 90% of the output power of the free-running bar. More than 90% of the laser emission was absorbed by Rb cell.