Light signal receiver with preamplification function and dual polarization means

摘要

A light signal receiver in which an input of a preamplifier receives a so-called useful electric current output by a light-sensitive device. The preamplifier comprises an input stage having an input transistor assembled with a "common base" whose emitter is connected to the input of the preamplifier and whose base is kept at a fixed potential. A low input impedance and therefore a reduction of the influence of stray capacitance exhibited by the light-sensitive device results from this arrangement Further, a second input transistor can be utilized so that the preamplifier operates as a differential type preamplifier.