  This paper presents the design, fabrication, and experimental
characterization of monolithically integrated p-n junction InGaN/GaN multiple
quantum well diodes (MQWDs) and suspended waveguides. Suspended MQWDs can be
used as transmitters and receivers simultaneously, and suspended waveguides are
used for light coupling to create an in-plane visible light communication
system. Compared to the waveguide with separation trench, the calculated total
light efficiency is increased from 18% to 22% for the continuous waveguide. The
MQWDs are characterized by their typical current-voltage performance, and the
pulse excitation measurements confirm that the InGaN/GaN MQWDs can achieve the
light emission and photodetection at the same time. The photocurrent
measurements indicate that the photocurrent is modulated by a bias voltage and
that the photons are being supplied from another transmitter. An experimental
demonstration is presented showing that the proposed device works well for
in-plane full-duplex communication using visible light.
