Laser control loop with automatic adaptation to the monitoring signal polarity

US6539036B2 · kind B2 · utility

Assignee

• Thomson Licensing · FR

Inventors

• Steffen Lehr · Erbach, DE
• Rudiger Brunheim

Key dates

• Filing date: Dec 18, 2000
• Grant date: Mar 25, 2003
• Expiry date: May 24, 2021

Classification

• Technology area (CPC H): Electricity
• CPC primary: H01S5/042
• WIPO field: Optics
• WIPO sector: Instruments

Abstract

The invention relates to a method and a circuit arrangement for a laser control loop with automatic adaptation to the monitoring signal polarity. Use is made of a single-phase method which consists in that a signal produced by the monitor during the starting phase of the laser control loop is compared with a reference value, and in accordance with the result of the comparison the signal produced by the monitor is fed directly or inverted to the comparator for controlling the light power of the laser during the starting phase of the laser control loop. A signal is produced which initially feeds the comparator for controlling the light power the inverted monitoring signal, or directly feeds the monitoring signal, in a fashion always independent of the monitoring signal polarity, but dependent on the polarity of a reference value, and feeds it in a non-inverted fashion in the case of a monitoring signal running up to the reference value. The laser control loop circuit according to the invention ensures that the monitoring signal is fed with a fixed polarity to the first comparator before the reference value for controlling the light power is reached. This is achieved by virtue of the …