An optoelectronic detector with linear gain for light measurements and optical communication

Darlington amplifiers employing a current divider in a feedback circuit consisting of a combination of lateral and vertical transistors were developed. The realization of detector circuits with integrated amplifiers of this type is described. The cut-off frequency observed for units having a gain of about 200 was typically 7 MHz. Excellent gain linearity down to the pA-level makes these photodetectors particularly suitable for low level light detection.