Optoelectronic readout with an injection laser

An investigation was made of the possibility of utilizing an injection heterolaser in optical devices for data retrieval. An injection laser was used both as a source and detector of its own radiation reflected from a data carrier (optoelectronic readout). The influence of the reflected radiation was due to quasisteady modulation of the Q factor of the resonator, which was accompanied by modulation of the voltage across the laser diode. A study was made of the influence of the pump current on the useful signal and it was found that this current was related to the differential resistance of the laser diode.