High-power (cw) in-phase locked ‘‘Y’’ coupled laser arrays

Abstract
Buried heterostructure phased array lasers have been fabricated with ‘‘Y’’ coupling regions to produce in‐phase locking. The far‐field pattern corresponding to the in‐phase emission of ten waveguides is stable under wide variations of operating conditions. Power outputs of up to 200 mW cw and 400 mW pulsed are obtained from a ten‐element (50 μm aperture) array. By monitoring the far‐field pattern under impulse excitation, the phase locking is shown to evolve in less than 300 ps.