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US 5,335,109 AGranted
Optical receiver with extended dynamic range
AssigneeAlcatel
InventorRolf Heidemann
Life of this patent
Estimating the term…
Abstract
An optical amplifier is provided through which an incoming optical signal passes before entering an optical-to-electric transducer. The level of the optical signal output by the optical amplifier is controlled by a controller based on the electrical signal output by the transducer.
Claims15
An optical receiver for an optical communication system for receiving an optical input signal and producing an electrical output signal, comprising:
- an optical amplifier for receiving an incoming optical signal at an input thereof and producing an optical output signal at an output thereof;
- an optical-to-electrical transducer means operatively coupled to receive the optical output signal from the optical amplifier, wherein the incoming optical signal passes through the optical amplifier before entering the transducer means, the optical-to-electrical transducer means converting the received optical signal into the electrical output signal and providing the electrical output signal at an output of the receiver;
- and
- control means, operatively coupled to the optical amplifier and to the optical-to-electrical transducer means, for controlling the optical amplifier to adjust the level of the optical signal output by the optical amplifier based on the electrical output signal output by the transducer means;
- wherein said control means comprises level detector means for receiving the electrical output signal from the transducer means and determining the instantaneous average value of the electrical output signal, and automatic gain control means for receiving the instantaneous average value from the level detector means and producing a control voltage output signal to control the level of the optical signal output by the optical amplifier.
2 more elements
An optical receiver including an optical to electrical transducer device for receiving an optical input signal and producing an electrical output signal, the device comprising:
- fiber-optic pre-amp means for receiving the optical input signal and producing an amplified optical output signal, the fiber-optic pre-amp means including a series connection of a first pump-light filter, an amplifying fiber and a second pump-light filter, and having a pump source coupled to provide pump light to the amplifying fiber by a pump coupler;
- transducer means, operatively coupled to receive the output of the fiber-optic pre-amp means, for converting the optical output of the fiber-optic pre-amp means into an electrical signal;
- electrical pre-amp means, operatively coupled to receive the electrical signal from the transducer means, for amplifying the electrical signal from the transducer means to produce the electrical output signal of the device;
- and
- feedback control means, operatively coupled to receive the electrical output signal from the pre-amp means, for producing a level control signal and supplying the level control signal to the fiber-optic pre-amp means to control the level of optical amplification by controlling the pump light.
2 more elements
An optical receiver for optical communications systems, said receiver comprising:
- an optical preamp for receiving an optical input communications signal and producing an amplified optical output communications signal, the optical preamp including a control voltage input for receiving an external control voltage;
- an optical-to-electrical transducer, coupled to the optical preamp for receiving the amplified optical output communications signal and producing an electrical output communications signal;
- an electrical preamp, coupled to the optical-to-electrical transducer for receiving the electrical output communications signal and producing an amplified electrical output communications signal;
- a level detector, coupled to the electrical preamp for receiving the amplified electrical output communications signal and producing a level signal output dependent on the instantaneous average value of the amplified electrical output communications signal;
- and
- an automatic gain control circuit, coupled to the level detector for receiving the level signal output and producing a control voltage output signal, and coupled to the optical preamp control voltage input to provide the control voltage output signal thereto for controlling the level of the amplified optical output communications signal produced by the optical preamp.
3 more elements
Dependencies are inferred from the claim text.