Phototransceiver Has QD Microcavity LED (Research Review)
Densely packed two-dimensional arrays of phototransceivers that detect, process and transmit image signals with high sensitivity and low power consumption are desirable for image-sensing applications. In an article in Electronics Letters 36(23) p1955, O Qasaimeh et al. from the University of Michigan and the University of Texas describe a low-power monolithically integrated phototransceiver consisting of a modulated barrier photodiode (MBPD) and an In0.4Ga0.6As/GaAs self-organized quantum dot (or QD) microcavity LED. As a light emitter in the phototransceiver circuit, the QD microcavity LED promises narrowband resonant emission, directional output and nearly singlemode operation. In addition, a high wall wall-plug efficiency can be obtained at low operating currents. The MBPD exhibits a responsivity of 1.8 103 A/W for 630 nm excitation. At an output wavelength of 980 nm, the phototransceiver features an optical gain of 18 dB and power dissipation of 110 W. The input required for both receiver and detector is just 10 nW.