Efficient Wavelength Tunable Hybrid Laser

A tunable hybrid laser has a gain chip and a wavelength selection chip. The wavelength selection chip includes a wavelength selective loop reflector. The wavelength selective loop reflector is configured to receive the amplified lightwave from the gain chip. The wavelength selective loop reflector includes a single optical coupler and a micro-ring resonator (MMR). The single optical coupler splits the amplified lightwave and provides portions thereof to different branches of the MRR. The MRR permits selection of a desired wavelength and reflects the portions of the amplified lightwave at the desired wavelength back to the single optical coupler, which combines the portions of the amplified lightwave at the desired wavelength to generate a reflection lightwave and a transmission lightwave. The reflection lightwave is returned to the gain chip to form the external cavity and the transmission lightwave is output from the tunable hybrid laser.