US3621273A
Expired / Lapsed
US
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Optical second harmonic generator
Assignee: COHERENT RADIATION
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Filing: 1970-03-05
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Granted: 1971-11-16
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Expires: 1990-03-05
Abstract
Abstract A device for providing an optical second harmonic output beam of coherent radiation such as light in response to an input beam of coherent radiation at the fundamental wavelength. A nonlinear crystal is provided within a vacuum sealed enclosure. The input light beam is provided through a first window forming an integral part of the enclosure and which is maintained at Brewster''s angle to the incoming beam. A second window orthogonally oriented relative to the first window is provided for maximizing the resulting second harmonic wavelength output beam which is polarized 90* relative to the fundamental beam. Means are also provided for automatically maintaining the crystal at a predetermined temperature. During operation, the enclosure is evacuated of substantially all air, including water vapor.
Inventors
- 👤 Robert J Rorden
- 👤 Mark W Dowley
- 👤 Wayne S Mefferd
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 20:37
CPC Classifications
G; G02; G02F; G02F1/00; G02F1/35; G02F1/37; G05; G05D; G05D23/00; G05D23/19; G05D23/20; G05D23/24
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
139 words
Optical second harmonic generator for use with a laser or maser comprising: a. a crystal capable of producing radiation of a second harmonic wavelength in response to a beam of radiation at a fundamental wavelength; b. means for mounting said crystal; c. means for maintaining said crystal at a predetermined temperature; d. means for encapsulating said crystal within a substantially airtight enclosure adaptable to maintain said crystal in a substantially vacuum environment; and e. wherein said encapsulating means includes as an integral part thereof a first window in alignment with the axis of said crystal at Brewster''s angle to incoming beams of radiation, and a second window oriented substantially orthogonally with respect to said first window and in axial alignment with the axis of said crystal and at Brewster''s angle to the resulting second harmonic wavelength beam which results.
Claim 2
Dependent Claim
139 words
Optical second harmonic generator for use with a laser or maser comprising: a. a crystal capable of producing radiation of a second harmonic wavelength in response to a beam of radiation at a fundamental wavelength; b. means for mounting said crystal; c. means for maintaining said crystal at a predetermined temperature; d. means for encapsulating said crystal within a substantially airtight enclosure adaptable to maintain said crystal in a substantially vacuum environment; and e. wherein said encapsulating means includes as an integral part thereof a first window in alignment with the axis of said crystal at Brewster''s angle to incoming beams of radiation, and a second window oriented substantially orthogonally with respect to said first window and in axial alignment with the axis of said crystal and at Brewster''s angle to the resulting second harmonic wavelength beam which results.
Claim 3
Dependent Claim
69 words
Optical second harmonic generator as in claim 1 wherein said temperature maintaining means comprises: i. a thermoelectric heat exchange device in a heat conducting relationship with said crystal; ii. a heat sink in a heat conducting relationship with said thermoelectric heat exchange device; and iii. circuit means responsive to the temperature of said crystal for maintaining said crystal at said predetermined temperature by regulating said thermoelectric heat exchange device.
Claim 4
Dependent Claim
35 words
Optical second harmonic generator as in claim 2 wherein said ciRcuit means includes first means in thermal contact with said crystal and responsive to the temperature of said crystal for providing a temperature-related electrical signal.
Claim 5
Dependent Claim
18 words
Optical second harmonic generator as in claim 3 including second means for monitoring the temperature of said crystal.
Claim 6
Dependent Claim
23 words
Optical second harmonic generator as in claim 4 wherein said first and second means each comprise thermistors thermally in contact with said crystal.
Claim 7
Dependent Claim
28 words
Optical second harmonic generator as in claim 3 wherein said heat sink includes a cooling chamber therein and an inlet and outlet of passage of a coolant therethrough.
Claim 8
Dependent Claim
18 words
Optical second harmonic generator as in claim 1 including a sealable vacuum nozzle connected to said airtight enclosure.
Claim 9
Dependent Claim
25 words
Second harmonic generator as in claim 2 wherein said crystal mounting means comprises an aluminum housing mounted to said thermoelectric device and enclosing said crystal.
Claim 10
Dependent Claim
21 words
Second harmonic generator as in claim 1 wherein said crystal is of NH4H2PO4 and said predetermined temperature is approximately -11* C.
Claim 11
Dependent Claim
21 words
Second harmonic generator as in claim 1 wherein said crystal is of KH2PO4 and said predetermined temperature is approximately -11* C.
Claim 12
Dependent Claim
37 words
Second harmonic generator as in claim 1 including first optical means for reducing the cross-sectional area of said fundamental wavelength radiation upon passing through said crystal and second optical means for recollimating said resulting second harmonic radiation.
Claim 13
Dependent Claim
19 words
Second harmonic generator as in claim 11 wherein each of said first and second optical means comprises convex lenses.
Claim 14
Dependent Claim
40 words
Second harmonic generator as in claim 1 wherein said encapsulating means comprises a. a base member; b. a cover including as a portion thereof said first and second windows; and c. means for sealingly securing said cover to said base.
Claim 15
Dependent Claim
59 words
Second harmonic generator as in claim 13 wherein said base member is circular and includes a circumferentially located beveled-rim portion; and wherein said securing means includes an O-ring receivable within said beveled-rim portion of said base member; and a threaded retaining ring adaptable with said threaded base for forcibly securing said O-ring in an airtight relationship with said cover.
Claim 16
Dependent Claim
47 words
Optical second harmonic generator as in claim 3 wherein said circuit means comprises a resistance bridge circuit including in one branch thereof said first means, and amplifying means for regulating said thermoelectric heat exchange device in response to bridge imbalances caused by variations in said electrical signals.
Claim 17
Dependent Claim
27 words
Optical second harmonic generator as in claim 15 wherein said amplifying means comprises an operational amplifier coupled with at least one transistor operating in the amplifying mode.
Claim 18
Dependent Claim
27 words
Optical second harmonic generator as in claim 15 including at least one variable resistor in another branch of said bridge circuit for selectively adjusting said predetermined temperature.
Claim 19
Dependent Claim
18 words
Optical second harmonic generator as in claim 17 including current limiting means for said thermoelectric heat exchange device.
Claim 20
Dependent Claim
122 words
Optical second harmonic generator as in claim 15 wherein said first means comprises a thermistor; wherein said heat sink includes a cooling chamber therein and an inlet and outlet for passage of a coolant therethrough; wherein said crystal is of NH4H2PO4 and said predetermined temperature is approximately -11* C.; and wherein said encapsulating means comprises a base member; a cover including as a portion thereof said first and second windows; and means for sealingly securing said cover to said base; and including first optical means for limiting the cross-sectional area of said fundamental wavelength radiation upon passing through said crystal and second optical means for recollimating said resulting second harmonic radiation and including a sealable vacuum nozzle connected to said airtigHt enclosure.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-11-15 | 1975-05-17 | 1975-11-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-11-15 | 1979-05-17 | 1979-11-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-11-15 | 1983-05-17 | 1983-11-16 | $7700.00 | Window Closed / Lapsed |