Efficient Wavelength Tunable Hybrid Laser

A tunable hybrid laser, comprising:

• a gain chip configured to generate an amplified lightwave;
• and
• a wavelength selection chip evanescently coupled to the gain chip, the wavelength selection chip comprising a phase control section and a wavelength selective loop reflector, the phase control section configured to pass the amplified lightwave received from the gain chip to the wavelength selective loop reflector, the wavelength selective loop reflector including a single optical coupler and at least one micro-ring resonator (MRR), the single optical coupler configured to split the amplified lightwave and provide portions of the amplified lightwave to different branches of the at least one MRR, the at least one MRR configured to permit selection of a desired wavelength and to reflect the portions of the amplified lightwave at the desired wavelength back to the single optical coupler, the single optical coupler configured to combine the portions of the amplified lightwave at the desired wavelength to generate a reflection lightwave and a transmission lightwave, the reflection lightwave returned to the gain chip via the phase control section to form the external cavity and the transmission lightwave output from the tunable hybrid laser.