Integrated light emitting/receiving amplifier element

摘要

An integrated light amplifier in which a stripe laser is formed over a substrate and then a vertical phototransistor is formed over the laser. Electrodes are attached to the back of the substrate and to the top of the phototransistor with the phototransistor electrode being formed with a hole so that incident light can reach the phototransistor. Before formation of the substrate electrode, the substrate can be ground to the desired thickness. Photocarriers are detected and multiplied in the phototransistor and injected into the stripe laser. Additional electrodes may be provided over the laser in order to bias the laser independently of the incident light.