A system (100; 200; 300; 400; 600; 700), comprising: a laser (102; 202; 602; 702) configured to emit a light beam ; a resonator (104; 204; 604; 706) configured to receive the light beam emitted by the laser and return a feedback light beam to the laser such that the feedback light beam causes injection locking of the laser to the resonator; and a non-reciprocal optical assembly (106; 608; 704) interposed between and optically coupled to the laser and the resonator, the non-reciprocal optical assembly comprises: a first port configured to receive the light beam from the laser; and a second port configured to output the light beam to the resonator and receive the feedback light beam from the resonator; wherein the first port is further configured to output the feedback light beam to the laser; wherein the light beam passes through the non-reciprocal optical assembly from the first port to the second port with a first power loss, and the feedback light beam passes through the non-reciprocal optical assembly from the second port to the first port with a second power loss; and characterized in that the laser is configured to emit the light beam at a power greater than 50 mW, and the non-reciprocal optical assembly is configured to output the light beam to the resonator at a power less than 3 mW. a laser (102; 202; 602; 702) configured to emit a light beam ; a resonator (104; 204; 604; 706) configured to receive the light beam emitted by the laser and return a feedback light beam to the laser such that the feedback light beam causes injection locking of the laser to the resonator; and a non-reciprocal optical assembly (106; 608; 704) interposed between and optically coupled to the laser and the resonator, the non-reciprocal optical assembly comprises: a first port configured to receive the light beam from the laser; and a second port configured to output the light beam to the resonator and receive the feedback light beam from the resonator; wherein the first port is further configured to output the feedback light beam to the laser; wherein the light beam passes through the non-reciprocal optical assembly from the first port to the second port with a first power loss, and the feedback light beam passes through the non-reciprocal optical assembly from the second port to the first port with a second power loss; and characterized in that the laser is configured to emit the light beam at a power greater than 50 mW, and the non-reciprocal optical assembly is configured to output the light beam to the resonator at a power less than 3 mW. a first port configured to receive the light beam from the laser; and a second port configured to output the light beam to the resonator and receive the feedback light beam from the resonator; wherein the first port is further configured to output the feedback light beam to the laser; wherein the light beam passes through the non-reciprocal optical assembly from the first port to the second port with a first power loss, and the feedback light beam passes through the non-reciprocal optical assembly from the second port to the first port with a second power loss; and characterized in that the laser is configured to emit the light beam at a power greater than 50 mW, and the non-reciprocal optical assembly is configured to output the light beam to the resonator at a power less than 3 mW. <EOS>