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US 5,929,430 AGranted
Coupled opto-electronic oscillator
AssigneeCalifornia Institute of Technology
InventorsX. Steve Yao, Lute Maleki
Life of this patent
Estimating the term…
Abstract
A coupled opto-electronic oscillator that directly couples a laser oscillation with an electronic oscillation to simultaneously achieve a stable RF oscillation at a high frequency and ultra-short optical pulsation by mode locking with a high repetition rate and stability. Single-mode selection can be achieved even with a very long opto-electronic loop. A multimode laser can be used to pump the electronic oscillation, resulting in a high operation efficiency. The optical and the RF oscillations are correlated to each other.
Claims57
An opto-electronic device, comprising:
- a laser, having an internal active optical feedback loop with a first loop gain greater than unity and responsive to an electrical modulation signal, said laser operating to produce a coherent optical oscillation;
- and
- an opto-electronic feedback loop with a second loop gain greater than unity, receiving an optical signal indicative of said optical oscillation and converting said optical signal into said electrical modulation signal having a relation with said optical oscillation, said electrical modulation signal affecting said optical loop and said optical oscillation.
An opto-electronic device, comprising:
- an active optical feedback loop configured to have a first loop gain greater than unity and operable to produce a laser oscillation therein, said optical loop having an electro-optical element operable to affect said first loop gain;
- and
- an opto-electronic feedback loop having a second loop gain greater than unity and being coupled with said optical loop, said opto-electronic loop including a photodetector that receives an optical signal indicative of said laser oscillation in said optical loop and produces an electrical modulation signal, wherein said electrical modulation signal is fed into said electro-optical element in said optical loop to couple said optical loop and said opto-electronic loop with each other.
An opto-electronic device, comprising:
- an active optical feedback loop with a first loop gain greater than unity and a first loop delay, said optical loop operable to generate a laser oscillation therein and having an electro-optical gain element that is operable to affect said first loop gain;
- and
- an opto-electronic feedback loop coupled with said optical loop, having a second loop gain greater than unity and a second loop delay greater than said first loop delay, said opto-electronic loop including:
- an optical delay line having one end coupled to said optical loop to receive an optical signal indicative of said laser oscillation and another end connected to a photodetector that converts said optical signal into an electrical modulation signal,
- an RF delay line having one end connected to said photodetector to receive said electrical modulation signal and another end connected to said electro-optical gain element, and
- an RF bandpass filter connected in said RF delay line, having a center frequency that is substantially equal to a RF beat frequency of different modes of said optical loop, whereby said optical loop is mode-locked to produce pulsed laser oscillations.
3 more elements
A method for generating an opto-electronic oscillation, comprising:
- providing an active optical feedback loop with a first loop gain greater than unity and responsive to an electrical modulation signal, said optical loop operating to produce a laser oscillation;
- providing an opto-electronic loop with a second loop gain greater than unity, said opto-electronic loop having an optical delay line with a photodetector and an RF delay line;
- optically coupling said optical delay line of said opto-electronic loop with said optical loop to receive an optical signal indicative of said laser oscillation;
- converting said optical signal into said electrical modulation signal with said photodetector, said electrical modulation signal having a relation with said laser oscillation;
- and
- electrically coupling said RF delay line with said optical loop to feed said electrical modulation signal to affect said optical loop.
3 more elements
An opto-electronic device, comprising:
- a semiconductor gain medium formed on a substrate and operable to produce an optical gain in response to an electrical excitation signal;
- two reflective elements formed on said substrate and spaced from each other to enclose said semiconductor gain medium, one of said reflective elements being partially transmissive to allow transmission of light generated by said semiconductor gain medium, wherein said semiconductor gain medium and said reflective elements form an optical loop which operable to produce a first loop gain greater than unity and to sustain a laser oscillation;
- and
- an opto-electronic feedback loop having a second loop gain greater than unity and an optical fiber coupled to said substrate to receive a portion of transmitted light from one of said reflective elements, wherein said opto-electronic loop includes a photodetector coupled to convert light from said optical fiber into an electrical modulation signal,
- wherein said electrical modulation signal is applied to said semiconductor gain medium to modulate said first loop gain and to couple said optical loop and said opto-electronic loop with each other.
2 more elements
Dependencies are inferred from the claim text.