Circuit arrangement for amplitude-modulating the drive signal of a laser

The universally-applicable circuit arrangement of the invention makes possible an adjustment procedure for holding emitted optical power of a laser constant independent of temperature and aging. This circuit arrangement may be carried out as a three-stage cascade circuit supplied with operating voltages greater than 5 V. In accordance with the purpose of the invention, a circuit arrangement is provided which is universally applicable in a temperature range T=-40 DEG C. to 100 DEG C. for commercially available lasers and can be supplied by a standard 5 V source. In order to accomplish this as per the invention, differential amplifiers acting as current switches are arranged in a first cascade stage and the current sources feeding the differential amplifiers arranged in a second cascade stage. A data signal (D) serving to control the modulating current (Imod) is logically combined with a pilot signal (P) serving to control the pilot currents (IP1, IP2) in at least one cascade stage.