US3681709A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Diffraction coupled laser oscillator focusing system
Assignee: RTX Corp
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Filing: 1970-01-27
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Granted: 1972-08-01
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Expires: 1990-01-27
Abstract
Abstract A plurality of mirrors is arranged in spaced relationship forming a laser oscillator cavity, a diffraction coupler and a focusing system. The oscillator cavity is formed between a concave mirror and a flat centrally located compound convex mirror, the cavity being proportioned to provide oscillation of the laser electromagnetic energy in the fundamental mode and the convex mirror being formed to diffract laser energy out of the oscillator. An annular mirror positioned intermediate to said concave and convex mirrors, collects said diffracted energy and focuses it as a nearly diffraction limited laser spot at the work area.
Inventors
- 👤 Clyde Owen Brown
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 14:53
CPC Classifications
H; H01; H01S; H01S3/00; H01S3/05; H01S3/08; H01S3/081; H01S3/0818
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
263 words
A gas laser comprising: a plurality of mirrors forming an optical resonator cavity having a laser oscillation region of length L uniformly disposed about an axis through said mirrors; a first one of said mirrors having a spherical concave reflection surface with a radius of curvature R14 forming one end of the cavity and defining one end of the oscillation region wherein the radius of curvature Rk14 is greater than twice the length L; a second one of said mirrors having a compound reflection surface comprising a spherical convex reflection surface with a radius of curvature R16 positioned symmetrically about a central flat reflection surface, the flat surface of radius a being normal to said axis and disposed with respect to the first mirror to define the other end of the oscillation region which supports oscillation with a mode pattern radius of w measured at the flat surface, the convex surface reflecting diffracted energy out of the oscillation region and away from said axis; and a third mirror having a spherical annular concave reflection surface with a radius of curvature R26 facing said convex surface, said surface including a centrally located hole of radius b therethrough to allow passage of the laser oscillations between said first mirror and said flat surface, the dimension b, w and a being interdependent according to the relation b> w> a, said third mirror being coaxially disposed about said axis and positioned a distance d from the flat reflection surface to convergingly reflect the diffracted energy from said convex surface to an area external of the oscillation region.
Claim 2
Dependent Claim
263 words
A gas laser comprising: a plurality of mirrors forming an optical resonator cavity having a laser oscillation region of length L uniformly disposed about an axis through said mirrors; a first one of said mirrors having a spherical concave reflection surface with a radius of curvature R14 forming one end of the cavity and defining one end of the oscillation region wherein the radius of curvature Rk14 is greater than twice the length L; a second one of said mirrors having a compound reflection surface comprising a spherical convex reflection surface with a radius of curvature R16 positioned symmetrically about a central flat reflection surface, the flat surface of radius a being normal to said axis and disposed with respect to the first mirror to define the other end of the oscillation region which supports oscillation with a mode pattern radius of w measured at the flat surface, the convex surface reflecting diffracted energy out of the oscillation region and away from said axis; and a third mirror having a spherical annular concave reflection surface with a radius of curvature R26 facing said convex surface, said surface including a centrally located hole of radius b therethrough to allow passage of the laser oscillations between said first mirror and said flat surface, the dimension b, w and a being interdependent according to the relation b> w> a, said third mirror being coaxially disposed about said axis and positioned a distance d from the flat reflection surface to convergingly reflect the diffracted energy from said convex surface to an area external of the oscillation region.
Claim 3
Dependent Claim
71 words
A gas laser according to claim 1 wherein the diameter ''2b'' of the hole in said third mirror is sufficiently large to allow oscillations of the laser in the fundamental mode to pass therethrough unimpeded, and sufficiently small to permit said third mirror to intercept all of the diffracted energy reflected by said convex surface, and wherein a power coupling factor defined as is maintained between approximately thirty and forty percent.
Claim 4
Dependent Claim
31 words
A gas laser according to claim 1 wherein the flat surface of said second mirror has a diameter ''2a'' to provide a Fresnel number of approximately one for the oscillation region.
Claim 5
Dependent Claim
36 words
A gas laser according to claim 1 wherein the convex surface of said second mirror and the concave surface of said third mirror define only an unstable resonator in the region therebetween according to the relationship
Claim 6
Dependent Claim
200 words
In a gas laser, apparatus for the production and utilization of laser energy comprising: a pair of mirrors forming an optical resonator cavity having a laser oscillation region uniformly disposed about an axis through said mirrors; the first one of said mirrors having a concave reflection surface forming one end of the cavity and defining one end of the oscillation region; the second one of said mirrors having a compound reflection surface comprising a convex reflection surface positioned symmetrically about a central flat reflection surface which defines diffraction edge and is normal to said axis, the flat surface, cooperating with the first mirror to form the oscillation region and defining the other end thereof, the convex surface reflecting diffracted energy out of the oscillation region and away from said axis; and a third annular mirror having a concave reflection surface of diameter D, the third mirror positioned intermediate to said pair of mirrors and concentric about said axis and further positioned to intercept and focus all the diffracted energy from said convex surface to an area external of the oscillation region which is separated from the third mirror by a distance f, wherein the ratio of f:D is approximately four.
Claim 7
Dependent Claim
200 words
In a gas laser, apparatus for the production and utilization of laser energy comprising: a pair of mirrors forming an optical resonator cavity having a laser oscillation region uniformly disposed about an axis through said mirrors; the first one of said mirrors having a concave reflection surface forming one end of the cavity and defining one end of the oscillation region; the second one of said mirrors having a compound reflection surface comprising a convex reflection surface positioned symmetrically about a central flat reflection surface which defines diffraction edge and is normal to said axis, the flat surface, cooperating with the first mirror to form the oscillation region and defining the other end thereof, the convex surface reflecting diffracted energy out of the oscillation region and away from said axis; and a third annular mirror having a concave reflection surface of diameter D, the third mirror positioned intermediate to said pair of mirrors and concentric about said axis and further positioned to intercept and focus all the diffracted energy from said convex surface to an area external of the oscillation region which is separated from the third mirror by a distance f, wherein the ratio of f:D is approximately four.
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) | 1975-08-01 | 1976-01-31 | 1976-08-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-08-01 | 1980-01-31 | 1980-08-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-08-01 | 1984-01-31 | 1984-08-01 | $7700.00 | Window Closed / Lapsed |