Optical amplifier

US5499135A · kind A · utility

Assignee

• Alcatel N.V. · NL

Inventors

• Rolf Heidemann · Zöblitz, DE
• Thomas Pfeiffer · Kumhausen, DE
• Manfred Kaiser · Karben, DE

Key dates

• Filing date: Oct 14, 1994
• Grant date: Mar 12, 1996
• Expiry date: Oct 14, 2014

Classification

• Technology area (CPC H): Electricity
• CPC primary: H01S3/09408
• WIPO field: Optics
• WIPO sector: Instruments

Abstract

Known optical amplifiers, which are used in a light transmission path to amplify the light signals to be transmitted, have the disadvantage that the semiconductor lasers, used as pump lasers therein, are very sensitive to feedback. According to the invention, the operating current of such pump lasers (4) is modulated at a high frequency, which causes the pump laser to operate in a multi-mode, thereby making it insensitive to feedback. For example, the operating current is DC, on which AC is superimposed. In the event the optical amplifier has two pump lasers, their operating current is also modulated. Both pump lasers are then advantageously alternately switched on and off at a sufficiently high switching frequency, which also prevents reciprocal interference.