US4803694A
Expired / Lapsed
US
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Laser resonator
Assignee: Amada Co Ltd
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Filing: 1987-07-08
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Granted: 1989-02-07
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Expires: 2007-07-08
Abstract
Abstract To generate a laser beam of significantly higher quality and high output power without damaging the output coupler (mirror), a novel stable optical laser resonator includes, in particular, a retro-reflector having an aspherical concave mirror for correcting intracavity wavefront aberrations induced when the laser beam travels through the lasing medium. The optimal surface constants of the geometry of the aspherical mirror are determined by an optical interferometry technique, an geometrical ray-tracing technique, and computer-aided ray tracing technique.
Inventors
- 👤 Chun-Sheu Lee
- 👤 Stanley L. Ream
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 12:37
CPC Classifications
H; H01; H01S; H01S3/00; H01S3/05; H01S3/08; H01S3/08018; H01S3/0804; H01S3/0805; H01S3/08045
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
120 words
A laser resonator having a cavity for the propagation of a laser beam having a wavefront in which a lasing medium is positioned, comprising: (a) a retro-reflector means including: (1) optical means disposed in said cavity for expanding the wavefront leaving the lasing medium; and (2) aspherical concave mirror means disposed in said cavity facing said optical means for reflecting the expanded wavefront toward the lasing medium again and correcting wavefront aberrations induced when the laser beam passes through the lasing medium; and (b) output coupler means arranged facing said retro-reflector means with the lasing medium positioned within an intracavity formed between said output coupler means and said optical means, for providing feedback for regenerative action of the laser beam.
Claim 2
Dependent Claim
120 words
A laser resonator having a cavity for the propagation of a laser beam having a wavefront in which a lasing medium is positioned, comprising: (a) a retro-reflector means including: (1) optical means disposed in said cavity for expanding the wavefront leaving the lasing medium; and (2) aspherical concave mirror means disposed in said cavity facing said optical means for reflecting the expanded wavefront toward the lasing medium again and correcting wavefront aberrations induced when the laser beam passes through the lasing medium; and (b) output coupler means arranged facing said retro-reflector means with the lasing medium positioned within an intracavity formed between said output coupler means and said optical means, for providing feedback for regenerative action of the laser beam.
Claim 3
Dependent Claim
17 words
The laser resonator as set forth in claim 1, wherein said optical means is a divergent lens.
Claim 4
Dependent Claim
21 words
The laser resonator as set forth in claim 1, wherein said optical means comprises a convergent lens and a spatial filter.
Claim 5
Dependent Claim
20 words
The laser resonator as set forth in claim 1, wherein said aspherical concave mirror means is an aspherical concave mirror.
Claim 6
Dependent Claim
36 words
The laser resonator as set forth in claim 4, wherein said aspherical concave mirror has an aspherical reflecting surface from which the expanded wavefront becomes a planar wavefront after having passed through the lasing medium again.
Claim 7
Dependent Claim
29 words
The laser resonator as set forth in claim 3, wherein said spatial filter eliminates higher-order aberrations in the laser beam, while said aspherical concave mirror means corrects lower-order aberrations.
Claim 8
Dependent Claim
38 words
The laser resonator as set forth in claim 4, wherein geometry of said aspherical concave mirror is defined by the following equation: ##EQU3## where Z=surface sag; S=radius; CURV=curvature; A, B, C, D=aspherical deformation constants; and K=the conic constant.
Claim 9
Dependent Claim
84 words
The laser resonator as set forth in claim 7, wherein optimal surface constants CURV, A, B, C, D, and K are determined in accordance with: (a) an interference fringe pattern observed by means of optical interferometry technique; (b) an optical-pathlength difference map representative of the relationship between the optical-pathlength difference and aperture position and calculated by means of geometrical ray-tracing technique; and (c) variation in the optical-pathlength difference map through selection of proper surface parameters minimized by means of a computer-aided ray tracing technique.
Claim 10
Dependent Claim
23 words
The laser resonator as set forth in claim 4, wherein said aspherical concave mirror includes a reflection surface formed by a diamondmachining apparatus.
References Cited (Backward Citations)
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| 3.5 Years (Year 4) | 1992-02-07 | 1992-08-08 | 1993-02-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-02-07 | 1996-08-08 | 1997-02-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-02-07 | 2000-08-08 | 2001-02-07 | $7700.00 | Window Closed / Lapsed |