LASER DRIVING CURRENT CONTROL CIRCUIT

摘要

Control circuit for controlling a laser drive current. In known control circuits certain levels of the optical output signal are kept constant. This renders it difficult to satisfy certain requirements during the life of the laser as regards the linearity of the modulation of the optical output signal. In the described control circuit the intermodulation of two signals present in the modulation signal with substantially constant amplitudes is measured, an error signal which controls a component of the drive current being derived therefrom.