US5365531A
Expired / Lapsed
US
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Apparatus and method for initializing an optical-fiber laser for mode locking
Assignee: Agilent Technologies Inc
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Filing: 1992-11-24
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Granted: 1994-11-15
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Expires: 2012-11-24
Abstract
Abstract A figure-8 loop laser having a controllable phase shifter in a Sagnac loop (non-linear amplifying loop mirror). A half-wave plate in series with Faraday optical rotators provide a switchable non-reciprocal 180-degree phase shifter that allows the birefringence of the fiber loop to be adjusted during continuous wave operation. The phase shifter is activated during continuous wave operation to find a minimum threshold and then is turned off, placing the laser in optimum state for mode locking.
Inventors
- 👤 Hong Lin
- 👤 Wayne V. Sorin
- 👤 David K. Donald
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 20:18
CPC Classifications
H; H01; H01S; H01S3/00; H01S3/10; H01S3/11; H01S3/1106; H01S3/1112; H01S3/05; H01S3/06; H01S3/063; H01S3/067; H01S3/06791; H01S3/06708; H01S3/06712
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
113 words
A fiber loop laser comprising: a fiber loop having an output coupler; a Sagnac loop, optically coupled to the fiber loop to define an optical path, having an input coupler receiving excitation energy; wherein the optical path includes the fiber loop and the Sagnac loop; polarization compensation means in the optical path; an amplifying medium in the optical path, operative to amplify a light signal in the optical path sufficiently to cause to the laser to oscillate; wherein the output coupler extracts a portion of the amplified light signal; and a controllable phase shifter in the optical path, operative to introduce a non-reciprocal phase shift before mode-lock to initialize the laser for mode-locking.
Claim 2
Dependent Claim
113 words
A fiber loop laser comprising: a fiber loop having an output coupler; a Sagnac loop, optically coupled to the fiber loop to define an optical path, having an input coupler receiving excitation energy; wherein the optical path includes the fiber loop and the Sagnac loop; polarization compensation means in the optical path; an amplifying medium in the optical path, operative to amplify a light signal in the optical path sufficiently to cause to the laser to oscillate; wherein the output coupler extracts a portion of the amplified light signal; and a controllable phase shifter in the optical path, operative to introduce a non-reciprocal phase shift before mode-lock to initialize the laser for mode-locking.
Claim 3
Dependent Claim
16 words
A laser as in claim 1 wherein the controllable phase shifter comprises a non-reciprocal phase shifter.
Claim 4
Dependent Claim
18 words
A laser as in claims 2 wherein the non-reciprocal phase shifter comprises a plurality of Faraday optical rotators.
Claim 5
Dependent Claim
20 words
A laser as in claim 2 and further comprising a piezo-electric phase shifter in series with the non-reciprocal phase shifter.
Claim 6
Dependent Claim
15 words
A laser as in claim 1 wherein the controllable phase shifter comprises a phase modulator.
Claim 7
Dependent Claim
18 words
A laser as in claim 5 and further comprising modulating means to modulate the phase modulator over time.
Claim 8
Dependent Claim
15 words
A laser as in claim 6 wherein the modulating means comprises an optical signal generator.
Claim 9
Dependent Claim
15 words
A laser as in claim 6 wherein the modulating means comprises an electrical signal generator.
Claim 10
Dependent Claim
76 words
A fiber loop laser comprising: a single mode fiber loop including an optical isolator, a first polarization controller, and an output coupler in a series connection; a Sagnac loop including a second polarization controller, an amplifying medium operative to amplify an optical signal, an input coupler which receives excitation energy from an external source, and a controllable phase shifter in a series connection; and optical coupling means coupling the fiber loop and the Sagnac loop together.
Claim 11
Dependent Claim
76 words
A fiber loop laser comprising: a single mode fiber loop including an optical isolator, a first polarization controller, and an output coupler in a series connection; a Sagnac loop including a second polarization controller, an amplifying medium operative to amplify an optical signal, an input coupler which receives excitation energy from an external source, and a controllable phase shifter in a series connection; and optical coupling means coupling the fiber loop and the Sagnac loop together.
Claim 12
Dependent Claim
18 words
A fiber loop laser as in claim 9, wherein the controllable phase shifter comprises a non-reciprocal phase shifter.
Claim 13
Dependent Claim
20 words
A fiber loop laser as in claim 10, wherein the non-reciprocal phase shifter comprises a plurality of Faraday optical rotators.
Claim 14
Dependent Claim
24 words
A fiber loop laser as in claim 10, and further comprising a piezo-electric phase shifter in the Sagnac loop with the non-reciprocal phase shifter.
Claim 15
Dependent Claim
17 words
A fiber loop laser as in claim 9, wherein the controllable phase shifter comprises a phase modulator.
Claim 16
Dependent Claim
19 words
A fiber loop laser as in claim 13, further comprising modulating means to modulate the phase modulator in time.
Claim 17
Dependent Claim
17 words
The fiber loop laser as in claim 14, wherein the modulating means comprises an optical signal generator.
Claim 18
Dependent Claim
17 words
The fiber loop laser as in claim 14, wherein the modulating means comprises an electrical signal generator.
Claim 19
Independent Claim
49 words
A method of initializing a laser for mode-locking, comprising the steps of: introducing a non-reciprocal phase shift into the laser; placing the laser in continuous wave operation; adjusting birefringence within the laser to optimize the laser for mode-locking; introducing a reciprocal phase shift into the laser; and initiating mode-locking.
Claim 20
Independent Claim
49 words
A method of initializing a laser for mode-locking, comprising the steps of: introducing a non-reciprocal phase shift into the laser; placing the laser in continuous wave operation; adjusting birefringence within the laser to optimize the laser for mode-locking; introducing a reciprocal phase shift into the laser; and initiating mode-locking.
Claim 21
Independent Claim
49 words
A method of initializing a laser for mode-locking, comprising the steps of: introducing a reciprocal phase shift into the laser; placing the laser in continuous wave operation; adjusting birefringence within the laser to optimize the laser for mode-locking; introducing a non-reciprocal phase shift into the laser; and initiating mode-locking.
Claim 22
Independent Claim
49 words
A method of initializing a laser for mode-locking, comprising the steps of: introducing a reciprocal phase shift into the laser; placing the laser in continuous wave operation; adjusting birefringence within the laser to optimize the laser for mode-locking; introducing a non-reciprocal phase shift into the laser; and initiating mode-locking.
References Cited (Backward Citations)
US4323310A
Cited
US5050183A
Cited
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| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1997-11-14 | 1998-05-16 | 1998-11-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-11-14 | 2002-05-16 | 2002-11-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-11-14 | 2006-05-16 | 2006-11-15 | $7700.00 | Window Closed / Lapsed |