Monolithic integration of a heterojunction transistor with a multiple quantum well modulator

The t-SEED, which is the integration of a multiple quantum well (MQW) modulator with a phototransistor, was proposed by P. Wheatley et al. (1987) as an optical logic device. The device performs logic operations on optical inputs and gives an optical output. The output power is larger than the input power-the device has gain-so that cascadable logic is possible. It is envisaged that arrays of t-SEEDs could be used in optical parallel processing architectures, such as optical implementations of neural networks and image processors