  High-performance integrated optical phased arrays (OPAs) are crucial for
building up energy-efficient solid-state beam steering systems on a chip. This
work demonstrates a first heterogeneous III-V/Si phase-shifter based OPA that
utilizes III-V multiple quantum well (MQW) structures to provide superior
performance. Demonstrated phase shifters have Vpi of only 0.45 V and residual
amplitude modulation (RAM) of only 0.15 dB at 1550 nm for 2pi phase shift with
low power consumption of less than 3 nW, which are, to the best our knowledge,
the state-of-the-art performance with a record low operating voltage, low power
consumption, and low RAM in on-chip OPAs. Their bandwidth is >1 GHz across 200
nm wavelength range. Wavelength tuning is used to demonstrate two-dimensional
beam steering with a field of view of 28x51 degree in the 32-channel OPA with
an emitter-array pitch of 2 um. Side-mode suppression ratio of 16 dB is also
achieved. The high-performance heterogeneous OPA paves the way for scalable and
efficient on-chip beam steerers with large steering range and high beam
quality.
