US3628044A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Second harmonic laser
Assignee: Lockheed Martin Corp
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Filing: 1969-04-14
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Granted: 1971-12-14
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Expires: 1989-04-14
Abstract
Abstract An improved second harmonic laser comprises a resonant cavity having disposed in axial alignment therein an active laser material, a second harmonic generating crystal, an electro-optic polarizing crystal and a polarization selector. The output end of the laser cavity comprises a pair of mirrors which have different preselected reflecting properties with respect to the fundamental and second harmonic laser wavelengths.
Inventors
- 👤 Donald S Young
- 👤 John S Hancock
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 11:17
CPC Classifications
H; H01; H01S; H01S3/00; H01S3/10; H01S3/106; H01S3/107; H01S3/108; H01S3/109; H01S3/05; H01S3/08; H01S3/08086; H01S3/0809
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
258 words
An improved second harmonic laser structure comprising in combination an active laser element, a light source for optically pumping said laser element to produce output energy having a predetermined fundamental frequency and polarization, a second harmonic generating medium disposed adjacent said laser element and responsive to said fundamental frequency energy to convert at least a portion thereof to energy at the second harmonic having polarization which is orthogonal to said fundamental energy, a reflective coating disposed on the surface of said harmonic generating medium adjacent said laser element said coating being substantially 100 percent reflective of second harmonic energy and 100 percent transmissive of said fundamental energy, means disposed adjacent said harmonic generating medium for selectively rotating the polarization of said fundamental and second harmonic energy, means disposed adjacent said polarization rotating means for selectively directing said fundamental and second harmonic energy in one of first and second preselected directions as a function of the polarization thereof, and means for defining an optical cavity including a first reflector disposed adjacent said active laser element opposite said harmonic generating medium and substantially 100 percent reflective of both said fundamental and said second harmonic energy, a second reflector disposed in said first preselected direction with respect to said directing means and substAntially 100 percent reflective of said second harmonic and 100 percent transmissive of said fundamental energy, and a third reflector disposed in said second preselected directions with respect to said directing means and substantially 100 percent transmissive of said second harmonic and 100 percent reflective of said fundamental energy.
Claim 2
Dependent Claim
258 words
An improved second harmonic laser structure comprising in combination an active laser element, a light source for optically pumping said laser element to produce output energy having a predetermined fundamental frequency and polarization, a second harmonic generating medium disposed adjacent said laser element and responsive to said fundamental frequency energy to convert at least a portion thereof to energy at the second harmonic having polarization which is orthogonal to said fundamental energy, a reflective coating disposed on the surface of said harmonic generating medium adjacent said laser element said coating being substantially 100 percent reflective of second harmonic energy and 100 percent transmissive of said fundamental energy, means disposed adjacent said harmonic generating medium for selectively rotating the polarization of said fundamental and second harmonic energy, means disposed adjacent said polarization rotating means for selectively directing said fundamental and second harmonic energy in one of first and second preselected directions as a function of the polarization thereof, and means for defining an optical cavity including a first reflector disposed adjacent said active laser element opposite said harmonic generating medium and substantially 100 percent reflective of both said fundamental and said second harmonic energy, a second reflector disposed in said first preselected direction with respect to said directing means and substAntially 100 percent reflective of said second harmonic and 100 percent transmissive of said fundamental energy, and a third reflector disposed in said second preselected directions with respect to said directing means and substantially 100 percent transmissive of said second harmonic and 100 percent reflective of said fundamental energy.
Claim 3
Dependent Claim
40 words
Apparatus as recited in claim 1 wherein said directing means is effective to direct energy having the polarization of said fundamental energy emitted by said laser element in said first direction and energy having orthogonal polarization in said second direction.
Claim 4
Dependent Claim
47 words
Apparatus as recited in claim 1 wherein said polarization rotating means comprises an electro-optic polarizing crystal and a variable voltage source coupled to said crystal whereby the polarization of energy passing therethrough is rotated in accordance with the voltage level coupled from said source to said crystal.
Claim 5
Dependent Claim
17 words
Apparatus as recited in claim 3 wherein said polarizing crystal is a deuterated potassium dihydrogen phosphate crystal.
Claim 6
Dependent Claim
63 words
Apparatus as recited in claim 3 further including means for sequentially controlling the voltage from said source to levels corresponding to the half-wave voltage at said fundamental frequency whereby the polarization of said fundamental energy is rotated through 90*, substantially zero voltage, and the half-wave voltage at said second harmonic frequency whereby the polarization of said second harmonic energy is rotated through 90*.
Claim 7
Dependent Claim
28 words
Apparatus as recited in claim 1 wherein said active laser element is an yttrium aluminum garnet element, and said harmonic generating medium comprises a barium sodium niobate crystal.
References Cited (Backward Citations)
US3487230A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-12-13 | 1975-06-14 | 1975-12-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-12-13 | 1979-06-14 | 1979-12-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-12-13 | 1983-06-14 | 1983-12-14 | $7700.00 | Window Closed / Lapsed |