Tunable dual-wavelength operation of a diode array with an external grating-loaded cavity

Abstract

A novel grazing-incidence grating cavity has been developed for simultaneous generation of laser output at two wavelengths. The gain section is a commercial laser diode array. By moving vertically with respect to the optical axis V-shaped double slit at the end mirror, we demonstrate tuning of the spectral separation of the dual-wavelength laser output from 3.52 to 11.29 nm. The side-mode suppression ratio is 10-20 dB. Examination of the far-field patterns reveal that the laser mode at the two wavelengths corresponds to a different order of the array modes.