Monolithically integrated low-power phototransceivers for optoelectronic parallel sensing and processing applications

A low-power GaAs-based monolithically integrated phototransceiver, consisting of a high-gain heterojunction phototransistor (WPT) and a microcavity light-emitting diode (MCLED) or a low-threshold vertical-cavity surface-emitting laser (VCSEL), is demonstrated. The HPT and MCLED/VCSEL are grown by molecular-beam epitaxy in a single step. The phototransistor exhibits a responsivity of 60 A/W at an input power of 1 /spl mu/W. The input and output wavelengths are 850 and 980 nm, respectively. The MCLED-based phototransceiver exhibits an optical gain of 7 dB and power dissipation of 400 /spl mu/W for an input power of 1.5 /spl mu/W. The small signal modulation bandwidth is 80 MHz. On the other hand, the VCSEL-based phototransceiver exhibits an optical gain of 10 dB and power dissipation of 760 /spl mu/W for an input power of 2.5 /spl mu/W.