US3869210A
Expired / Lapsed
US
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Laser system with an antiresonant optical ring
Assignee: National Aeronautics and Space Administration
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Filing: 1973-11-02
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Granted: 1975-03-04
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Expires: 1993-11-02
Abstract
Abstract Various applications of an antiresonant ring, consisting of a beam splitter and a number of optical reflectors, are disclosed. With a beam splitter having a transmission coefficient t1 and a reflection coefficient r1 where t1 r1, an optical beam incident on the beam splitter along a first axis is split into two components which circulate around the ring in opposite directions and are recombined to reflect back the beam along the first axis, with none of the beam power being directed along a second axis. The ring can be used as part of the cavity of two otherwise independent lasers, with two separate laser mediums external to the ring, or with a multi-wavelength laser medium in the ring. The ring together with a second-harmonic generation crystal and a dispersive phase shifter in the ring can be used to generate the second harmonic of an optical beam. By proper incorporation of phase shifting means in the ring, optical pulse switching, laser mode locking, and/or laser cavity dumping can be achieved.
Inventors
- 👤 James C Administrator Fletcher
- 👤 Anthony E Siegman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 23:58
CPC Classifications
H; H01; H01S; H01S3/00; H01S3/10; H01S3/11; H01S3/1106; H01S3/1109; H01S3/05; H01S3/08; H01S3/081; H01S3/083; H01S3/06; H01S3/07; H01S3/082; H01S3/106; H01S3/108; H01S3/109; H01S3/1103; H01S3/1123; H01S3/115
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
227 words
An optical system comprising: an antiresonant optical ring including a beam splitter with a beam splitting face responsive to an optical beam directed thereto along a first axis for reflecting a first portion of said beam along a second axis, and for transmitting a second portion of said beam through said beam splitting face, and means for directing said reflected first beam portion back to said beam splitting face along said first axis and for directing said transmitted second beam portion back to said beam splitting face along said second axis, whereby said first and second beam portions circulate in said ring in opposite directions, said beam splitting face being characterized by a transmissiion coefficient definable as t1 and a reflection coefficient definable as r1 whereby said beam splitter reflects along said second axis some of said first beam portion which is directed thereto, and transmits some of said first beam portion along said first axis, and further reflects along said first axis some of said second beam portion which is directed thereto, and transmits some of said second beam portion along said second axis; means exterior to said ring for directing said optical beam to said beam splitting face along said first axis; and phase control means inside said ring for controlling the relative phases of the first and second beam portions circulating in said ring.
Claim 2
Dependent Claim
227 words
An optical system comprising: an antiresonant optical ring including a beam splitter with a beam splitting face responsive to an optical beam directed thereto along a first axis for reflecting a first portion of said beam along a second axis, and for transmitting a second portion of said beam through said beam splitting face, and means for directing said reflected first beam portion back to said beam splitting face along said first axis and for directing said transmitted second beam portion back to said beam splitting face along said second axis, whereby said first and second beam portions circulate in said ring in opposite directions, said beam splitting face being characterized by a transmissiion coefficient definable as t1 and a reflection coefficient definable as r1 whereby said beam splitter reflects along said second axis some of said first beam portion which is directed thereto, and transmits some of said first beam portion along said first axis, and further reflects along said first axis some of said second beam portion which is directed thereto, and transmits some of said second beam portion along said second axis; means exterior to said ring for directing said optical beam to said beam splitting face along said first axis; and phase control means inside said ring for controlling the relative phases of the first and second beam portions circulating in said ring.
Claim 3
Dependent Claim
49 words
The system as described in claim 1 wherein said phase control means inside said ring comprise a phase shifter and signal source means for applying a signal to said phase shifter to control the magnitude of the phase shift experienced by any beam portion passing through said phase shifter.
Claim 4
Dependent Claim
14 words
The system as described in claim 2 wherein t1 is substantially equal to r1.
Claim 5
Dependent Claim
37 words
The system as described in claim 2 wherein said means for directing of said ring comprise at least a first reflective mirror located along said first axis and a second reflective mirror located along said second axis.
Claim 6
Dependent Claim
70 words
The system as described in claim 1 further including a second-harmonic generation medium in said ring for converting at least part of a beam portion of a fundamental frequency, definable as omega , into a beam portion of a frequency 2 omega and said phase control means comprise dispersive phase shifting means of a preselected length having different indices of refraction for beams at frequencies omega and 2 omega .
Claim 7
Dependent Claim
14 words
The system as described in claim 5 wherein t1 is substantially equal to r1.
Claim 8
Dependent Claim
37 words
The system as described in claim 5 wherein said means for directing of said ring comprise at least a first reflective mirror located along said first axis and a second reflective mirror located along said second axis.
Claim 9
Dependent Claim
223 words
An optical system comprising: an antiresonant optical ring including a beam splitter having a beam splitting face with first and second opposite sides and with a transmission coefficient t1 and a reflection coefficient r1 of either of said sides, where t1 r1 and at least first and second ring beam reflective mirrors, positioned with respect to one another and said beam splitter, whereby a first optical beam direcTed to the first side of said beam splitting face along a first axis propagates through said ring as two components propagating in opposite directions which are recombined by said beam splitter at said beam splitting face into a first beam which is directed back only along said first axis from said beam splitter, and whereby a second optical beam directed to the second side of said beam splitting face along a second axis which is perpendicular to said first axis, propagates through said ring as two components propagating in opposite directions which are recombined at said beam splitter into said second beam which is directed back only said second axis from said beam splitter; first means along said first axis for directing said first optical beam to said beam splitter along said first axis; and second means along said second axis for directing said second optical beam to said beam splitter along said second axis.
Claim 10
Dependent Claim
223 words
An optical system comprising: an antiresonant optical ring including a beam splitter having a beam splitting face with first and second opposite sides and with a transmission coefficient t1 and a reflection coefficient r1 of either of said sides, where t1 r1 and at least first and second ring beam reflective mirrors, positioned with respect to one another and said beam splitter, whereby a first optical beam direcTed to the first side of said beam splitting face along a first axis propagates through said ring as two components propagating in opposite directions which are recombined by said beam splitter at said beam splitting face into a first beam which is directed back only along said first axis from said beam splitter, and whereby a second optical beam directed to the second side of said beam splitting face along a second axis which is perpendicular to said first axis, propagates through said ring as two components propagating in opposite directions which are recombined at said beam splitter into said second beam which is directed back only said second axis from said beam splitter; first means along said first axis for directing said first optical beam to said beam splitter along said first axis; and second means along said second axis for directing said second optical beam to said beam splitter along said second axis.
Claim 11
Dependent Claim
88 words
The system as described in claim 8 wherein said first means comprise a first external mirror and a first laser medium for producing said first optical beam and for directing the first beam to said beam splitter and for responding to the first beam which is directed therefrom, and said second means comprise a second external mirror and a second laser medium for producing said second optical beam along said second axis and for responding to the second beam directed from said beam splitter along said second axis.
Claim 12
Dependent Claim
32 words
The system as described in claim 9 wherein said system further includes a medium in said ring responsive to the components of said first and second beams which propagate through said ring.
Claim 13
Dependent Claim
120 words
The system as described in claim 8 wherein said system further includes a multiwavelength laser medium for stimulating the emission of said first beam at a wavelength definable as lambda 1, and for stimulating the emission of said second beam at a wavelength definable as lambda 2, said first means comprising a first exterior mostly reflective mirror along said first axis for reflecting back to said beam splitter along said first axis most of the first beam directed thereto from said beam splitter, and said second means comprise a second exterior mostly reflective mirror along said second axis for reflecting back to said beam splitter along said second axis most of the second beam directed thereto from said beam splitter.
Claim 14
Dependent Claim
25 words
The system as described in claim 11 wherein said first and second exterior mirrors are optimized for the wavelengths lambda 1 and lambda 2, respectively.
Claim 15
Dependent Claim
203 words
An optical second harmonic generator comprising: laser means for producing an optical beam at an angular frequency omega along a first axis; an antiresonant optical ring including a beam splitter positioned along said first axis and first and second ring mirrors, with said beam splitter splitting the optical beam directed thereto into a first beam portion which is reflected to said first mirror and therefrom through said second mirror to said beam splitter, and into a second beam portion which is transmitted through said beam splitter to said second mirror, said second beam portion being successively reflected by said second and first mirrors to said beam splitter, said beam splitter transmitting a part of said first beam portion and reflecting a part of said second beam portion along said first axis, and reflecting a part of said first beam portion and transmitting a part of said second beam portion along a second axis; and means in said ring between said first and second mirrors for affecting the portions of the beam passing between said mirrors in both directions so that the combined parts of said first and second beam portions along said second axis are characterized by an angular frequency 2 omega .
Claim 16
Dependent Claim
203 words
An optical second harmonic generator comprising: laser means for producing an optical beam at an angular frequency omega along a first axis; an antiresonant optical ring including a beam splitter positioned along said first axis and first and second ring mirrors, with said beam splitter splitting the optical beam directed thereto into a first beam portion which is reflected to said first mirror and therefrom through said second mirror to said beam splitter, and into a second beam portion which is transmitted through said beam splitter to said second mirror, said second beam portion being successively reflected by said second and first mirrors to said beam splitter, said beam splitter transmitting a part of said first beam portion and reflecting a part of said second beam portion along said first axis, and reflecting a part of said first beam portion and transmitting a part of said second beam portion along a second axis; and means in said ring between said first and second mirrors for affecting the portions of the beam passing between said mirrors in both directions so that the combined parts of said first and second beam portions along said second axis are characterized by an angular frequency 2 omega .
Claim 17
Dependent Claim
162 words
The generator as described in claim 13 wherein said beam splitter is characterized by a transmission coefficient which is substantially equal to its reflection coefficient and wherein said means in said ring include A dispersive phase shifter of length l with an index of refraction n1 at the angular frequency omega and an index of refraction n2 at an angular frequency 2 omega , and a medium in series between said first and second mirrors, said medium converting the angular frequency of part of a beam of angular frequency omega passing therethrough in either direction into an angular frequency 2 omega , said phase shifter and said medium shifting and phase of the beam passing between said first and second mirrors in one direction by 2n1 omega l/c, c being the speed of light and the beam passing between the two mirrors in an opposite direction by 2n1 omega l/c so that 2(n1 - n2) omega l/c + or - pi .
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-03-03 | 1978-09-02 | 1979-03-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-03-03 | 1982-09-02 | 1983-03-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-03-03 | 1986-09-02 | 1987-03-04 | $7700.00 | Window Closed / Lapsed |