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US 6,580,532 B1Granted
Opto-electronic techniques for reducing phase noise in a carrier signal by carrier supression
AssigneeCalifornia Institute of Technology
InventorsSteve Yao, John Dick, Lute Maleki
Life of this patent
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Abstract
Systems and techniques for suppressing the carrier signal using an optical delay element and an electrical interferometer in an opto-electronic noise suppression module.
Claims64
An opto-electronic device, comprising:
- an oscillator to produce an oscillation signal at a carrier frequency, said oscillator responsive to a control signal to change a characteristic of said oscillation signal;
- and
- a noise suppression module coupled to said oscillator to produce said control signal in response to said oscillation signal, said noise suppression module including:
- an opto-electronic unit having an optical delay element and a photodetector to produce a first electrical signal indicative of said oscillation signal, and
- an electrical interferometer coupled to said opto-electronic unit to interfere said first electrical signal with a second electrical signal indicative of said oscillation signal to produce a first output signal representing a destructive interference and a second output signal representing a constructive interference;
- wherein said noise suppression module generates said control signal based on said first output signal from said electrical interferometer.
3 more elements
An opto-electronic device, comprising:
- an optical modulator, having an electrical input port to accept an electrical modulation signal and an optical input port to receive an input optical signal at an optical frequency, to generate an output optical signal which is modulated to carry an oscillation signal at an oscillation frequency related to said electrical modulation signal;
- and
- an opto-electronic unit, having an optical delay element coupled to receive at least a portion of said output optical signal and an electrical section coupled to said electrical input port to produce said electrical modulation signal, said electrical section including:
- a photodetector to receive an optical transmission from said optical delay element to produce a first electrical signal;
- an electrical interferometer coupled to receive said first electrical signal and a second electrical signal indicative of said oscillation signal to cause interference therebetween, to produce a first output signal representing a destructive interference and a second output signal representing a constructive interference;
- a signal mixer coupled to receive and mix said first output signal from said electrical interferometer and a local oscillator electrical signal indicative of said oscillating signal to produce a first control signal;
- and
- a phase shifting device coupled to control a phase of said second output signal from said electrical interferometer in response to said first control signal to produce said electrical modulation signal.
5 more elements
A method for controlling an electrical controlled oscillator that produces an oscillation signal at a carrier frequency, comprising:
- producing an optical signal that is modulated to carry the oscillation signal;
- transmitting said optical signal through an optical delay element to produce a delayed optical transmission signal;
- converting said optical transmission signal into a first electrical signal indicative of the oscillation signal,
- producing a second electrical signal indicative of the oscillation signal;
- interfering said first and said second electrical signals in an electrical interferometer to produce a first output signal representing a destructive interference and a second output signal representing a constructive interference;
- and
- applying said second output signal to control the oscillator.
4 more elements
An opto-electronic device for controlling an oscillator which produces an oscillation signal at a carrier frequency, comprising:
- an input port to receive an oscillation signal from an oscillator;
- an opto-electronic unit having an optical delay element and a photodetector to produce a first electrical signal indicative of the oscillation signal;
- an electrical interferometer coupled to said opto-electronic unit to interfere said first electrical signal with a second electrical signal indicative of the oscillation signal to produce a first output signal representing a destructive interference and a second output signal representing a constructive interference;
- and
- an output port to generate a control signal to the oscillator based on said first output signal from said electrical interferometer.
2 more elements
An opto-electronic device, comprising:
- an optical coupler having first and second input ports to receive input beams from two different lasers and first and second output ports;
- an optical delay element coupled to said first output port of said optical coupler;
- a first photodetector coupled to receive an output from said optical delay element to produce a first electrical signal;
- a second photodetector coupled to receive an output from said second output port of said optical coupler to produce a second electrical signal;
- an electrical interferometer having a first input to receive said first electrical signal and a second input to receive said second electrical signal, said electrical interferometer causing interference between said first and said second electrical signals to produce a first output signal representing a destructive interference and a second output signal representing a constructive interference;
- a signal mixer to mix said first and second output signals to produce a control signal based on said first output signal;
- and
- an output port to output said control signal.
5 more elements
Dependencies are inferred from the claim text.