Method and arrangement for controlling modulated lasers
AssigneeSiemens Aktiengesellschaft
InventorsWerner Dietrich, Franz Heiny
Life of this patent
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Abstract
A method and an arrangement for controlling modulated lasers are provided, in which an input signal of a laser is modulated by a pilot signal. The combined signal that is emitted is then utilized to control the laser. In order to substantially prevent individual spectral lines of the input signal from affecting the pilot signal, a pilot signal is selected with a frequency spectrum that is spread substantially uniformly in the spectral range of the input signal. Versions of this method are also known by the term “spread spectrum modulation”.
Claims14
A method for controlling modulated lasers, comprising the steps of:
- spreading a frequency spectrum of a pilot signal substantially uniformly at least over a section in a spectral operating range of a laser including a spectral range of an input signal;
- modulating the input signal of the laser by the pilot signal and emitting this combined signal by the laser;
- receiving the light emitted by the laser by a receiver element, thus producing a received signal;
- and
- evaluating and utilizing the received signal to control the laser.
An arrangement for controlling modulated lasers, comprising:
- a laser;
- a receiver element connected to the laser via an optical transmission path for receiving a received signal;
- a control unit having an input to receive an input signal to which the receiver element is connected, the control unit having an output that is connected to the laser;
- a pilot signal generator for generating a pilot signal;
- and
- a modulator for modulating the input signal by the pilot signal;
- the arrangement being utilized for:
- spreading a frequency spectrum of the pilot signal substantially uniformly at least over a section in a spectral operating range of the laser including a spectral range of the input signal;
- modulating an input signal of the laser by the pilot signal and emitting this combined signal by the laser;
- receiving the light emitted by the laser by the receiver element, thus producing the received signal;
- and
- evaluating and utilizing the received signal to control the laser.
Dependencies are inferred from the claim text.