Injection locking a laser-diode array with a phase-conjugate beam

Abstract

We use a mutually pumped phase conjugator to guide the output beam of a single-mode laser diode into the active region of a high-power laser-diode array. This injected beam locks the frequency of the array, causing it to emit a single, 1.45 times diffraction-limited, continuous-wave output beam containing 85% of the array’s total output power. Phase-conjugate injection dramatically improves the coupling into the laser array, so that less than a milliwatt of injected power is sufficient to lock all the array’s 450-mW output to the frequency of the master laser.