An approach towards hybrid integrated diode lasers for the visible spectra range

Integrating diode laser sources in the visible range into photonic circuits, for controlling wavelength tuning or for reducing the spectral linewidth, can enable, e.g., chip-sized multicolor light engines for life-science applications or drive multiple narrow-linewidth transitions in portable optical clocks. Current approaches with grating feedback and bulk or fiber optical beam combining lead to devices of appreciable size, restricted spectral control and suffer from mechanical perturbations. Hybrid integrated lasers, formed by a diode laser amplifier and a low-loss waveguide feedback circuit can avoid these disadvantages, but have only been realized at telecom wavelengths. We present our approach for realizing a first hybrid integrated diode-SiN laser in the visible, to generate light around 690 nm via optical feedback from an integrated micro-ring Vernier filter.