US5208819A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Optical source with frequency locked to an in-fiber grating resonantor
Assignee: Ciena Corp
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Filing: 1992-01-23
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Granted: 1993-05-04
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Expires: 2012-01-23
Abstract
Abstract A frequency stabilized optical signal source is provided. A laser (10) produces an optical carrier at a wavelength lambda . Feedback is provided to adjust the wavelength lambda . In order to provide the feedback, a portion of the optical carrier is modulated by a periodic reference signal (wrf). An optical fiber (16) with an in-fiber resonator (18) is coupled to receive the modulated optical carrier. The resonator effects a phase and/or amplitude change between the modulated optical carrier and a sideband thereof at a resonant frequency of the resonator. The phase or amplitude change is detected and used to adjust the laser wavelength. In a preferred embodiment, a moire grating having a single resonant frequency is used as the in-fiber resonator. The feedback scheme can lock either to the carrier frequency itself, or to a selected sideband of the modulated optical carrier. <IMAGE>
Inventors
- 👤 David R. Huber
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 02:52
CPC Classifications
H; H01; H01S; H01S3/00; H01S3/10; H01S3/13; H01S3/139; H01S3/1398; H01S5/00; H01S5/06; H01S5/068; H01S5/0683; H01S5/0687
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
112 words
A frequency stabilized optical signal source comprising: a laser for producing an optical carrier at a wavelength λ; means operatively associated with said laser for adjusting said wavelength λ; means for modulating said optical carrier by a periodic reference signal; an optical fiber coupled to receive the modulated optical carrier from said modulating means; a resonator within said optical fiber for effecting at least one of a phase and amplitude change between the modulated optical carrier and a sideband thereof at a resonant frequency of said resonator; means for detecting one of said phase and amplitude changes; and means responsive to said change detecting means for controlling said laser wavelength adjusting means.
Claim 2
Dependent Claim
112 words
A frequency stabilized optical signal source comprising: a laser for producing an optical carrier at a wavelength λ; means operatively associated with said laser for adjusting said wavelength λ; means for modulating said optical carrier by a periodic reference signal; an optical fiber coupled to receive the modulated optical carrier from said modulating means; a resonator within said optical fiber for effecting at least one of a phase and amplitude change between the modulated optical carrier and a sideband thereof at a resonant frequency of said resonator; means for detecting one of said phase and amplitude changes; and means responsive to said change detecting means for controlling said laser wavelength adjusting means.
Claim 3
Dependent Claim
20 words
A signal source in accordance with claim 1 wherein said resonator comprises a moire grating having a single resonant frequency.
Claim 4
Dependent Claim
31 words
A signal source in accordance with claim 2 wherein said controlling means lock said adjusting means to maintain λ at a wavelength that coincides with the resonant frequency of said grating.
Claim 5
Dependent Claim
42 words
A signal source in accordance with claim 1 wherein said detecting means comprise: a heterodyne detector in which a signal representative of said modulated optical carrier is mixed with a local oscillator frequency to produce a signal indicative of said phase change.
Claim 6
Dependent Claim
19 words
A signal source in accordance with claim 4 wherein said periodic reference signal is used as local oscillator frequency.
Claim 7
Dependent Claim
23 words
A signal source in accordance with claim 4 wherein said local oscillator frequency is a phase locked multiple of said periodic reference signal.
Claim 8
Dependent Claim
26 words
A signal source in accordance with claim 1 wherein said detecting means detect said change by identifying a unique signature produced thereby at said resonant frequency.
Claim 9
Dependent Claim
36 words
A signal source in accordance with claim 1 wherein said controlling means lock said adjusting means to maintain λ at a wavelength where the frequency of said sideband coincides with the resonant frequency of said resonator.
Claim 10
Dependent Claim
52 words
A signal source in accordance with claim 8 comprising: a plurality of local oscillators for providing different frequencies; and means for coupling a selected local oscillator to said detecting means; wherein the selection of a local oscillator determines which sideband of the modulated optical carrier is used to maintain said wavelength λ.
Claim 11
Dependent Claim
37 words
A signal source in accordance with claim 1 further comprising: means for splitting said optical carrier into a first portion for input to said modulating means and a second portion for use as a stable optical signal.
Claim 12
Dependent Claim
21 words
A signal source in accordance with claim 10 wherein said second portion comprises a substantial majority of the optical carrier power.
Claim 13
Dependent Claim
20 words
A signal source in accordance with claim 11 wherein said resonator comprises a moire grating having a single resonant frequency.
Claim 14
Dependent Claim
31 words
A signal source in accordance with claim 12 wherein said controlling means lock said adjusting means to maintain λ at a wavelength that coincides with the resonant frequency of said grating.
Claim 15
Dependent Claim
36 words
A signal source in accordance with claim 12 wherein said controlling means lock said adjusting means to maintain λ at a wavelength where the frequency of said sideband coincides with the resonant frequency of said resonator.
Claim 16
Dependent Claim
16 words
A signal source in accordance with claim 1 wherein said modulating means comprise a phase modulator.
References Cited (Backward Citations)
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