US4805182A
Expired / Lapsed
US
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RF-excited, all-metal gas laser
Assignee: Novanta Inc
•
Filing: 1987-10-19
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Granted: 1989-02-14
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Expires: 2007-10-19
Abstract
Abstract All-metal, RF-excited gas lasers employing organic or inorganic insulating material including polyimide and aluminum oxide to provide a structurally homogeneous laser capable of low-cost fabrication and broad temperature ranges suitable for military and commercial applications. A particularly novel embodiment employs an extruded housing and electrodes and relies almost solely upon gas conduction and gas convection cooling, obviating compression heat sinking. The latter embodiment can permit gas flow between the laser cavity and tube gas chambers through elongated gaps or spaces at the corners of the cavity. Insulators support the electrodes in a few places and facilitate simple, low-cost assembly. The latter geometry is also well adapted for use in folded configurations featuring multiple lasing sections and a common discharge electrode.
Inventors
- 👤 Peter Laakmann
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 11:09
CPC Classifications
H; H01; H01S; H01S3/00; H01S3/09; H01S3/097; H01S3/0975; H01S3/02; H01S3/03; H01S3/0315
Claims Analysis
Total Claims: 63
Claim 1
Independent Claim
89 words
An RF-excited gas laser, comprising: a pair of spaced, parallel metal plates; a pair of metal spacers separating said plates, said plates and spacers forming an elongated laser bore; a laser gas medium within said bore; and a pair of metal discharge electrodes located upon opposing surfaces within said bore and parallel to the longitudinal axis of said bore, said electrodes being excitable by a source of RF-excited voltage, said electrodes being electrically insulated from said opposing surfaces by nonconductive films between said electrodes and said opposing surfaces, respectively.
Claim 2
Dependent Claim
89 words
An RF-excited gas laser, comprising: a pair of spaced, parallel metal plates; a pair of metal spacers separating said plates, said plates and spacers forming an elongated laser bore; a laser gas medium within said bore; and a pair of metal discharge electrodes located upon opposing surfaces within said bore and parallel to the longitudinal axis of said bore, said electrodes being excitable by a source of RF-excited voltage, said electrodes being electrically insulated from said opposing surfaces by nonconductive films between said electrodes and said opposing surfaces, respectively.
Claim 3
Dependent Claim
18 words
The gas laser recited in claim 1 wherein said nonconductive films comprise an inorganic material such as polyimide.
Claim 4
Dependent Claim
19 words
The gas laser recited in claim 1 wherein said nonconductive films comprise an inorganic dielectric material such as mica.
Claim 5
Dependent Claim
18 words
The gas laser recited in claim 1 wherein said nonconductive films comprise an oxide of the electrode metal.
Claim 6
Dependent Claim
21 words
The gas laser recited in claim 1 wherein said nonconductive films comprise an oxide of the metal of said opposing surfaces.
Claim 7
Dependent Claim
23 words
The gas laser recited in claim 1 wherein the metals of said plates and of said spacers have substantially equal thermal expansion coefficients.
Claim 8
Dependent Claim
23 words
The gas laser recited in claim 1 wherein the metal of said plates and the metal of said spacers are the same metals.
Claim 9
Dependent Claim
28 words
The gas laser recited in claim 1 wherein the metal of said plates, the metal of said spacers, and the metal of said electrodes are the same metals.
Claim 10
Dependent Claim
21 words
The gas laser recited in claim 1 wherein said electrodes are excited by oppositely phased excitation voltages relative to ground potential.
Claim 11
Dependent Claim
24 words
The gas laser recited in claim 1 wherein said bore has a width and a height within the range of 0.1 to 0.4 inches.
Claim 12
Dependent Claim
21 words
The gas laser recited in claim 1 wherein the material used to form said plates, spacers, electrodes and insulators is aluminum.
Claim 13
Dependent Claim
12 words
The gas laser recited in claim 1 wherein the electrodes are anodized.
Claim 14
Dependent Claim
20 words
The gas laser recited in claim 1 wherein an additional insulator is applied to the electrode surface facing the bore.
Claim 15
Dependent Claim
21 words
The gas laser recited in claim 1 wherein said metal spacers are separated from said metal plates by an air gap.
Claim 16
Dependent Claim
25 words
The gas laser recited in claim 14 wherein the laser gas within the plasma communicates with external gas by convection transverse to the bore axis.
Claim 17
Dependent Claim
58 words
The gas laser recited in claim 14, further comprising a source of RF-excited voltage connected to said pair of metal discharge electrodes, the voltage generating a plasma in said elongated laser bore, substantially all of the heat generated by the plasma being carried away from the laser bore by conduction, convection and radiation through the laser gas medium.
Claim 18
Dependent Claim
68 words
An RF-excited gas laser comprising a plasma discharge section formed by a plurality of longitudinal electrodes separated from and contained within a larger envelope containing a laser gas medium, at least two of said electrodes surrounding and forming an axial laser bore, said electrodes being excitable by a source of RF voltage and being electrically insulated from each other in the discharge region by the laser gas medium.
Claim 19
Dependent Claim
68 words
An RF-excited gas laser comprising a plasma discharge section formed by a plurality of longitudinal electrodes separated from and contained within a larger envelope containing a laser gas medium, at least two of said electrodes surrounding and forming an axial laser bore, said electrodes being excitable by a source of RF voltage and being electrically insulated from each other in the discharge region by the laser gas medium.
Claim 20
Dependent Claim
61 words
The gas laser recited in claim 17, further comprising a source of RF voltage exciting said plurality of electrodes to generate a plasma in said plasma discharge section and means for transferring the heat generated by the discharge in said plasma from said plurality of electrodes to said larger envelope substantially by conduction, convection and radiation through the laser gas medium.
Claim 21
Dependent Claim
13 words
The gas laser recited in claim 17 wherein said electrodes have insulated surfaces.
Claim 22
Dependent Claim
56 words
The gas laser recited in claim 19 wherein the plurality of longitudinal electrodes comprise two orthogonally oriented pairs of electrodes, a first pair being excitable by a source of RF-excited voltage connected to said pair and the envelope, and a remaining pair of the two orthogonally oriented pairs of electrodes being substantially at electrically ground potential.
Claim 23
Dependent Claim
27 words
The gas laser recited in claim 20 wherein the position of the first pair of electrodes is defined by insulators located away from the axial laser bore.
Claim 24
Dependent Claim
30 words
The gas laser recited in claim 21 wherein said insulators are located at periodic longitudinal intervals and said insulators are of minimum contact area in order to reduce trapped gases.
Claim 25
Dependent Claim
28 words
The gas laser recited in claim 21 wherein the insulators serve as bearings during assembly, said assembly comprising the step of sliding the insulated electrodes into said envelope.
Claim 26
Dependent Claim
16 words
The gas laser recited in claim 23 wherein the insulators are made of a high-temperature plastic.
Claim 27
Dependent Claim
19 words
The gas laser recited in claim 23 wherein the insulators are made of glass, ceramic or other inorganic substance.
Claim 28
Dependent Claim
17 words
The gas laser recited in claim 21 wherein the insulators are an oxide of the extrusion metal.
Claim 29
Dependent Claim
42 words
The gas laser recited in claim 17 wherein the plurality of longitudinal electrodes comprise two orthogonally oriented pairs of electrodes, a first pair of said electrodes being driven by oppositely phased excitation voltages and a remaining pair being integral to said envelope.
Claim 30
Dependent Claim
41 words
The gas laser recited in claim 27 wherein the plasma discharge section formed by said pairs of electrodes is substantially square in cross section except for corner gaps serving as insulators, said gaps being a small fraction of the electrode width.
Claim 31
Dependent Claim
39 words
The gas laser recited in claim 27 wherein the envelope and the remaining pair of electrodes are formed from a unitary aluminum extrusion and the first pair of electrodes are made from oppositely facing pieces of additional aluminum extrusions.
Claim 32
Dependent Claim
27 words
The gas laser recited in claim 29 wherein said additional extrusions are provided with surfaces of large cross section to substantially optimize both conduction and convection cooling.
Claim 33
Dependent Claim
33 words
The gas laser recited in claim 17 comprising a plurality of electrodes to form a hollow discharge section of substantially closed circumference and having a plurality of RF voltages applied to said electrodes.
Claim 34
Dependent Claim
35 words
The gas laser recited in claim 17 wherein the laser gas medium contained within said envelope communicates with the laser gas medium in the plasma discharge section by convection transverse to the laser bore axis.
Claim 35
Dependent Claim
26 words
A gas laser as recited in claim 17 wherein the bore has a width and a height in the range between about 0.1 and 0.4 inch.
Claim 36
Dependent Claim
39 words
An RF-excited gas laser as recited in claim 17 wherein the heat transfer from the plasma to the envelope is accomplished by heat conduction through an electrically insulating layer of the laser gas disposed away from the discharge region.
Claim 37
Dependent Claim
33 words
An RF-excited gas laser as recited in claim 17 consisting of at least two substantially identical such discharge sections optically in series, such discharge sections being coupled with reflector elements having optical power.
Claim 38
Dependent Claim
15 words
The laser recited in claim 35 wherein said reflector elements fold said axial laser bore.
Claim 39
Dependent Claim
58 words
An RF-excited gas laser comprising a discharge section within a larger envelope containing a laser gas medium, said discharge section forming a laser bore and being defined by a plurality of longitudinal electrodes surrounding said laser bore, each carrying a different RF potential, substantially all surfaces contained within the envelope being directly exposed to the laser gas medium.
Claim 40
Dependent Claim
58 words
An RF-excited gas laser comprising a discharge section within a larger envelope containing a laser gas medium, said discharge section forming a laser bore and being defined by a plurality of longitudinal electrodes surrounding said laser bore, each carrying a different RF potential, substantially all surfaces contained within the envelope being directly exposed to the laser gas medium.
Claim 41
Dependent Claim
16 words
A gas laser as recited in claim 37 wherein said envelope and said electrodes are aluminum.
Claim 42
Dependent Claim
20 words
A gas laser as recited in claim 37 wherein the surfaces of said electrodes are covered with an oxide film.
Claim 43
Dependent Claim
25 words
A gas laser as recited in claim 37 wherein the laser gas medium within the discharge region communicates transversely to the laser bore by convection.
Claim 44
Dependent Claim
26 words
A gas laser as recited in claim 37 wherein the bore has a width and a height in the range between about 0.1 and 0.4 inch.
Claim 45
Dependent Claim
51 words
An RF-excited gas laser comprising a metal envelope, at least one pair of oxidized metal electrodes surrounding and forming a plasma discharge section within an axial laser bore formed by such electrodes, metal oxide insulating material between adjacent electrodes forming the laser bore, and a laser gas medium within said bore.
Claim 46
Dependent Claim
51 words
An RF-excited gas laser comprising a metal envelope, at least one pair of oxidized metal electrodes surrounding and forming a plasma discharge section within an axial laser bore formed by such electrodes, metal oxide insulating material between adjacent electrodes forming the laser bore, and a laser gas medium within said bore.
Claim 47
Dependent Claim
77 words
A gas laser as recited in claim 42 comprising an envelope consisting of a first aluminum extrusion having two projections forming two opposed electrodes of a first set of electrodes, a second set of opposed electrodes being formed by two sections of a second extrusion and held in fixed relationship to the envelope to complete a laser bore having a square cross section, said second set of electrodes being insulated from said first pair by metal oxide.
Claim 48
Dependent Claim
31 words
A gas laser as recited in claim 43 wherein substantially all heat is transferred from said metal electrodes to said envelope by conduction, convection and radiation through the laser gas medium.
Claim 49
Dependent Claim
28 words
A gas laser as recited in claim 43 wherein said additional extrusion has an enlarged surface area to optimize both conduction and convection cooling through the laser gas.
Claim 50
Dependent Claim
27 words
A gas laser as recited in claim 45, further comprising a plurality of support insulators located in areas away from the discharge to position the insulated electrodes.
Claim 51
Dependent Claim
26 words
A gas laser as recited in claim 42 wherein the bore has a width and a height in the range between about 0.1 and 0.4 inch.
Claim 52
Dependent Claim
55 words
An RF-excited gas laser comprising an axial tube containing an internal plasma discharge section wherein all surfaces contained within the tube are directly exposed to a laser gas medium, a plurality of longitudinal metal electrodes excitable by a source of RF voltage, and one or more separate insulators interposed between an electrode and discharge plasma.
Claim 53
Dependent Claim
55 words
An RF-excited gas laser comprising an axial tube containing an internal plasma discharge section wherein all surfaces contained within the tube are directly exposed to a laser gas medium, a plurality of longitudinal metal electrodes excitable by a source of RF voltage, and one or more separate insulators interposed between an electrode and discharge plasma.
Claim 54
Dependent Claim
112 words
An RF-excited gas laser, comprising: means defining at least one elongated chamber of substantially closed perimeter having a cross-sectional diameter less than about three percent of the chamber length, said chamber including a plurality of metal electrodes for establishing a transverse electric field, said electrodes extending in the length dimension, and insulating means for electrically insulating the electrodes from each other; a laser gas medium disposed in said at least one chamber; and means for establishing an alternating electric field along a direction transverse to the length of said at least one chamber, the alternating electric field having a frequency ranging from 10 MHz to 1 GHz to establish a laser-exciting plasma.
Claim 55
Dependent Claim
112 words
An RF-excited gas laser, comprising: means defining at least one elongated chamber of substantially closed perimeter having a cross-sectional diameter less than about three percent of the chamber length, said chamber including a plurality of metal electrodes for establishing a transverse electric field, said electrodes extending in the length dimension, and insulating means for electrically insulating the electrodes from each other; a laser gas medium disposed in said at least one chamber; and means for establishing an alternating electric field along a direction transverse to the length of said at least one chamber, the alternating electric field having a frequency ranging from 10 MHz to 1 GHz to establish a laser-exciting plasma.
Claim 56
Dependent Claim
15 words
The gas laser of claim 49 wherein said insulating means includes said laser gas medium.
Claim 57
Dependent Claim
35 words
The gas laser of claim 50 wherein said at least one elongated chamber is located within a sealed envelope and substantially all surfaces contained within the envelope are directly exposed to the laser gas medium.
Claim 58
Dependent Claim
21 words
The gas laser of claim 49 wherein said insulating means is formed by an oxide of the metal forming the electrodes.
Claim 59
Dependent Claim
31 words
The gas laser of claim 52 wherein substantially all of the heat generated in the plasma is conducted from the plasma to the envelope by conduction through the laser gas medium.
Claim 60
Dependent Claim
18 words
The gas laser of claim 49 wherein said insulating means is formed by coatings applied to said electrodes.
Claim 61
Dependent Claim
27 words
The gas laser of claim 49 wherein at least one metal electrode is electrically insulated from said plasma by additional insulating means transverse to the length dimension.
Claim 62
Dependent Claim
32 words
The gas laser of claim 49 wherein said elongated chamber is part of a sealed envelope and substantially all surfaces contained within said envelope are directly exposed to the laser gas medium.
Claim 63
Dependent Claim
15 words
The gas laser of claim 49, further comprising a plurality of substantially parallel, elongated chambers.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-02-14 | 1992-08-15 | 1993-02-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-02-14 | 1996-08-15 | 1997-02-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-02-14 | 2000-08-15 | 2001-02-14 | $7700.00 | Window Closed / Lapsed |