Single-port superluminescent-diode gain-chip for tunable single-wavelength and dual-wavelength blue-laser

Abstract

Reconfigurable photonic technology combining multiple functionalities in a single gain-chip is a crucial light-based platform for enabling hybrid applications. Here, we report on achieving a widely tunable and reconfigurable blue laser source using a single-port gain medium based on an InGaN/GaN superluminescent diode (SLD). As compared to tunable laser-diode emitters based solely on stimulated emission from a laser diode used as the gain medium, our amplified spontaneous emission system is capable of fast switching between the stimulated and amplified spontaneous emission regimes for on-demand use of time-incoherent, or time-coherent light with single- or dual-wavelengths. The single- and dual-wavelength laser tunability is designed using various external cavity (EC) configurations for a continuous selection and smooth transition of the emission wavelength from 436 nm–443 nm. Moreover, the InGaN SLD can amplify the optical power within the EC configuration by 6.5 dB. Thus, the prototype system opens up a viable route for designing reconfigurable light sources based on a single gain chip, and promises disruptive innovation for medical instrumentation, optical sensing technology, and optical communication.