High-power phase-locked arrays of index-guided diode lasers

Abstract

A nine-unit phase-locked array of index-guided channel-substrate-planar large-optical-cavity AlGaAs diode lasers is fabricated by one-step liquid phase epitaxial growth over a 5-μm period sawtooth grating etched into a GaAs substrate. Two-lobed, 180° phase shift operation is achieved to 75-mW cw power and to 400-mW peak pulsed power. Strong coherent optical coupling between the array units provides single-longitudinal-mode array operation to 80-mW cw output power. The cw and pulsed threshold currents are in the 250–400-mA range. Single-lobe, 0° phase shift operation, with the single beam peaked at 0°, is achieved to 200-mW peak power.