Method and circuit arrangement for correcting the light power output of a laser diode

US5313482A · kind A · utility

Assignee

• Linotype-Hell AG · DE

Inventors

• Thomas Zelenka · Troisdorf, DE
• Thomas Jacobsen · Kiel, DE
• Dietrich Asbach · Stralsund, DE

Key dates

• Filing date: Mar 5, 1993
• Grant date: May 17, 1994
• Expiry date: Mar 5, 2013

Classification

• Technology area (CPC H): Electricity
• CPC primary: H01S5/068
• WIPO field: Optics
• WIPO sector: Instruments

Abstract

The invention concerns a process and circuit for correcting the light-power output of a laser diode. The circuit comprises a generator (2) for generating a driver current (I.sub.T) which determines the light-power output of the laser diode. The driver current (I.sub.T) is modulated by a modulation signal (B). To correct the light-power output, the circuit includes a linear low-pass filter (5) which is acted on by the modulation signal (B) and which approximately simulates the change with time of the internal temperature of the laser diode (1) as a function of the modulation signal (B). The output signal of the linear low-pass filter (5) acts as a driver current (I.sub.T) correction signal (K), thus compensating for the temperature dependence of the laser-diode light-power output.