Dual-wavelength emission from a high-order Bragg gratings integrated broad-area laser diode

Abstract

This paper presents a broadband distributed Bragg reflection laser diode with dual-wavelength emission. The waveguide of the laser diode is integrated with a 95-um high-order Bragg grating (HOBG) region. Thus, the longitudinal mode of the broadband laser diode can be partially filtered by the HOBGs. As the gain peak of the active region can cover nearly four modes, two modes with nearly the same gain value can be emitted simultaneously. Moreover, two wavelengths with an interval of 0.25 nm are obtained, and the centre wavelength is near 958 nm. The maximum output power of the dual-wavelength emission can reach 411 mW at an operating current of 1.16 A. A stable dual-wavelength emission can be maintained when the operating current is changed from 1.02 A to 1.16 A. In particular, the spacing between the two wavelengths barely varies. Thus, dual-wavelength emission can be used for multi-wavelength continuous tuning applications.