Patent EP0486152A2 successfully refreshed from Google Patents.
EP0486152A2
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EP
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Gas slab laser
Assignee: Coherent Inc
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Filing: 1991-10-09
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Granted: —
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Expires: 2011-10-09
Abstract
Abstract A C0 2 slab waveguide laser (10) has a housing (20) sealed by end plates (22,24) and in- dudes a pair of spaced apart electrodes (36,38) having opposed light reflecting surfaces. The electrodes (36,38) are dimensioned in a manner to guide light in a plane perpendicular to the reflecting surfaces. Light parallel to the reflecting surfaces is not constrained other than by a pair of resonator mirrors (30,32). The resonator structure includes a negative branch unstable resonator in the nonwaveguide dimension, defined by the resonator mirrors (30,32). A stable resonator is used in the waveguide spacing dimension, but the resonator mirror spacing from the end of the guide is based in part on the configuration of the unstable resonator. A support structure (60) maintains the electrodes (36,38) in a spaced apart orientation without confining the discharge. Pipes (70,72) are provided for cooling the laser, and a sliding support (52) for accommodating thermal expansion of the parts. Adjustable mirror assemblies (26,28) are provided which allow the tilt angles of the resonator mirrors (30,32) to be varied from outside of the housing (20). The laser is capable of generating high energy short duration (less than 1 millisecond) pulses which can be used to treat tissue with reduced trauma.
Inventors
- 👤 James L. Hobart
- 👤 Joseph Dallarosa
- 👤 Phillip Gardner
- 👤 Wayne S. Mefferd
- 👤 Michael J. Yarborough
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-09 20:24
CPC Classifications
H; H01; H01S; H01S3/00; H01S3/02; H01S3/04; H01S3/041; H01S3/03; H01S3/0315; H01S3/038; H01S3/05; H01S3/08; H01S3/086; H01S3/09; H01S3/097; H01S3/0971; H01S3/09713; H01S3/0975
Claims Analysis
Total Claims: 44
Claim 1
Independent Claim
99 words
A slab laser comprising; a pair of elongated, spaced apart electrodes (36,38), having opposed, planar, light reflecting surfaces; a laser gas disposed between said electrodes (36,38); means (42) for exciting said laser gas to create a gas discharge; and a pair of mirrors (30,32) surrounding said electrodes (36,38) to define a resonant cavity, with the configuration of said mirrors (30,32) being selected such that a stable waveguide resonant cavity is defined in the plane perpendicular to said light reflecting surfaces (36,38) and a negative branch, unstable resonator is defined in the plane parallel to said light reflecting surfaces (36,38).
Claim 2
Dependent Claim
99 words
A slab laser comprising; a pair of elongated, spaced apart electrodes (36,38), having opposed, planar, light reflecting surfaces; a laser gas disposed between said electrodes (36,38); means (42) for exciting said laser gas to create a gas discharge; and a pair of mirrors (30,32) surrounding said electrodes (36,38) to define a resonant cavity, with the configuration of said mirrors (30,32) being selected such that a stable waveguide resonant cavity is defined in the plane perpendicular to said light reflecting surfaces (36,38) and a negative branch, unstable resonator is defined in the plane parallel to said light reflecting surfaces (36,38).
Claim 3
Dependent Claim
55 words
A slab laser according to claim 2, characterised in that the length of the electrodes (36,38) are chosen such that the radius of curvature of the wavefront of the laser beam in the waveguide dimension at the mirror location matches the radius of curvature of the mirrors (30,32) selected for the negative branch unstable resonator.
Claim 4
Dependent Claim
33 words
A slab laser according to claim 2, characterised in that said means for exciting the gas includes a RF generator (128,124,126) the output of which is coupled to one (120) of said electrodes.
Claim 5
Dependent Claim
175 words
An adjustable mirror assembly for attachment to the end of a housing (20) of a laser, said assembly comprising: an end plate (24) for attachment to the end of the housing (20) of said laser, wherein said attachment provides a vacuum seal between the assembly and the houseing (20), with the outer surface of said plate (24) having a circular groove (90) extending to a depth sufficient to define a flexure area (92) between the bottom of the groove (90) and the inner surface of the plate (24), and with the portion of the plate (24) radially inward of said groove (90) defining a tilt member (94); a mirror mount (96) for supporting a mirror (32), said mount (96) being connected to the inner surface of said plate (24), radially inwardly of said groove (90) and on said tilt member (94); and means (98,102), mounted to said plate (24) and outside of said housing (20) for applying a torque to said tilt member (94) in order to adjust the angle of said mirror mount (96).
Claim 6
Dependent Claim
175 words
An adjustable mirror assembly for attachment to the end of a housing (20) of a laser, said assembly comprising: an end plate (24) for attachment to the end of the housing (20) of said laser, wherein said attachment provides a vacuum seal between the assembly and the houseing (20), with the outer surface of said plate (24) having a circular groove (90) extending to a depth sufficient to define a flexure area (92) between the bottom of the groove (90) and the inner surface of the plate (24), and with the portion of the plate (24) radially inward of said groove (90) defining a tilt member (94); a mirror mount (96) for supporting a mirror (32), said mount (96) being connected to the inner surface of said plate (24), radially inwardly of said groove (90) and on said tilt member (94); and means (98,102), mounted to said plate (24) and outside of said housing (20) for applying a torque to said tilt member (94) in order to adjust the angle of said mirror mount (96).
Claim 7
Dependent Claim
70 words
An assembly according to claim 4, characterised in that said means for applying torque to the tilt member (94) consists of a plurality of pins (98), slidably mounted within said plate (24) radially outward of said groove (90) and about the circumference of said tilt member (94), with the radial position of said pins (98) being adjustable in a manner to place a varying torque on said tilt member (94).
Claim 8
Dependent Claim
125 words
An assembly for supporting an elongated element (38) within a laser housing (20), said housing (20) having opposed ends, said assembly comprising: a first support bracket (50) connected between one end of said housing (20) and one end of said element (38); and a second support bracket (52) connected to the other end of said element (52) having an elongated pin (54) projecting towards the other end of said housing (20), with said other end having a recess (56) for slidably receiving said pin (54) of said second support bracket (52), with the depth of said recess (56) being sufficient to allow the extent of said pin (54) within said recess (56) to vary as the element (38) thermally expands during operation of the laser.
Claim 9
Dependent Claim
125 words
An assembly for supporting an elongated element (38) within a laser housing (20), said housing (20) having opposed ends, said assembly comprising: a first support bracket (50) connected between one end of said housing (20) and one end of said element (38); and a second support bracket (52) connected to the other end of said element (52) having an elongated pin (54) projecting towards the other end of said housing (20), with said other end having a recess (56) for slidably receiving said pin (54) of said second support bracket (52), with the depth of said recess (56) being sufficient to allow the extent of said pin (54) within said recess (56) to vary as the element (38) thermally expands during operation of the laser.
Claim 10
Dependent Claim
19 words
An assembly according to claim 6, characterised in that said pin (54) and said recess (56) have complementary configurations.
Claim 11
Dependent Claim
14 words
An assembly according to claim 7, characterised in that said complementary configurations are cylindrical.
Claim 12
Dependent Claim
33 words
An assembly according to claim 6, characterised in that said element (38) is an electrode and said second support bracket (52) provides an electrical connection to said other end of the housing (20).
Claim 13
Independent Claim
128 words
An apparatus for cooling an electrically hot electrode within a laser housing comprising: an electrically grounded housing (20); an elongated conductive electrode (36) located within said housing (20), said electrode being connected to a power source (42); and means for cooling said electrode (36), said means including a fluid carrying conductive pipe (70) which passes into and through said housing (20), said pipe (70) including a center segment (74) which is in thermal contact with said electrode (36) and a pair of end segments which are spaced from said electrode (36) and grounded to said housing (20), said center segment (74) being joined to said end segments by insulative pipe sections (84) such that the center segment (74) can be electrically hot while said end segments remain grounded.
Claim 14
Independent Claim
128 words
An apparatus for cooling an electrically hot electrode within a laser housing comprising: an electrically grounded housing (20); an elongated conductive electrode (36) located within said housing (20), said electrode being connected to a power source (42); and means for cooling said electrode (36), said means including a fluid carrying conductive pipe (70) which passes into and through said housing (20), said pipe (70) including a center segment (74) which is in thermal contact with said electrode (36) and a pair of end segments which are spaced from said electrode (36) and grounded to said housing (20), said center segment (74) being joined to said end segments by insulative pipe sections (84) such that the center segment (74) can be electrically hot while said end segments remain grounded.
Claim 15
Dependent Claim
46 words
An apparatus according to claim 10, characterised in that said insulative pipe sections (84) are oriented such that the end segments of the pipe (70) are located near the housing wall and the center sgement (74) of the pipe is located closer to said electrode (36).
Claim 16
Dependent Claim
82 words
A slab laser comprising: a resonant cavity (30,32); a pair of elongated, spaced apart, planar elements (36,38) located within said cavity; a laser medium disposed between the inner surfaces of said elements (36,38); means (42) for exciting said laser medium; and means for cooling said elements (36,38), said means including fluid carrying pipes (70,72), and wherein the outer surfaces of said elements (36,38) are provided with elongated channels (76,78) for receiving at least a portion of said pipes (70,72) to maximize cooling.
Claim 17
Dependent Claim
82 words
A slab laser comprising: a resonant cavity (30,32); a pair of elongated, spaced apart, planar elements (36,38) located within said cavity; a laser medium disposed between the inner surfaces of said elements (36,38); means (42) for exciting said laser medium; and means for cooling said elements (36,38), said means including fluid carrying pipes (70,72), and wherein the outer surfaces of said elements (36,38) are provided with elongated channels (76,78) for receiving at least a portion of said pipes (70,72) to maximize cooling.
Claim 18
Dependent Claim
54 words
A slab laser according to claim 12, characterised in that said elements (36,38) are formed from a material having a different coefficient of thermal expansion than said pipes (70,72), and wherein said channels (76,78) in said elements (36,38) are located in a manner to minimize bending torque induced by heating of the elements (36,38).
Claim 19
Dependent Claim
23 words
A slab laser according to claim 13, characterised in that said channels (76,78) are located near the geometric center of said elements (36,38).
Claim 20
Dependent Claim
41 words
A slab laser according to claim 12, characterised in that said pipes (70,72) include at least one segment which is not located in said channels (76,78), and said segment of said pipes (70,72) includes a bend to allow for thermal expansion.
Claim 21
Dependent Claim
99 words
A slab laser comprising: a pair of elongated, spaced apart elements (36,38) each having a planar light reflecting surface, with said light reflecting surfaces being disposed so as to guide light only in a plane perpendicular to said surfaces; a laser gas disposed between said light reflecting surfaces; means (42) for exciting said laser gas to create a gas discharge; and means (60) for supporting said elements (36,38) in said spaced apart relationship, said means (60) being spaced away from said gas discharge such that the characteristics of said gas discharge are substantially unaffected by said support means (60).
Claim 22
Dependent Claim
99 words
A slab laser comprising: a pair of elongated, spaced apart elements (36,38) each having a planar light reflecting surface, with said light reflecting surfaces being disposed so as to guide light only in a plane perpendicular to said surfaces; a laser gas disposed between said light reflecting surfaces; means (42) for exciting said laser gas to create a gas discharge; and means (60) for supporting said elements (36,38) in said spaced apart relationship, said means (60) being spaced away from said gas discharge such that the characteristics of said gas discharge are substantially unaffected by said support means (60).
Claim 23
Dependent Claim
28 words
A slab laser according to claim 16, characterised in that said support means (60) is configured such that said gas discharge between said elements (36,38) is visually unobstructed.
Claim 24
Dependent Claim
30 words
A slab laser according to claim 16, characterised in that said support means is defined by a plurality of spaced apart, U-shaped, dielectric members (60) connected between said elements (36,38).
Claim 25
Dependent Claim
32 words
A slab laser according to claim 16, characterised in that said elements (36,38) are electrodes and said means (42) for exciting said gas functions to deliver an RF current to said electrodes.
Claim 26
Dependent Claim
53 words
A gas discharge tube comprising: a housing (20) for containing a gas; means (42) for exciting said gas to create a gas discharge; and means (110) for preionizing said gas to facilitate the creation of said gas discharge, said means including a light source for emitting photons to promote dissociation of said gas.
Claim 27
Dependent Claim
53 words
A gas discharge tube comprising: a housing (20) for containing a gas; means (42) for exciting said gas to create a gas discharge; and means (110) for preionizing said gas to facilitate the creation of said gas discharge, said means including a light source for emitting photons to promote dissociation of said gas.
Claim 28
Dependent Claim
17 words
A gas discharge tube according to claim 20, characterised in that said light source is a lamp.
Claim 29
Dependent Claim
17 words
A gas discharge tube according to claim 21 characterised in that said lamp is a mercury-argon lamp.
Claim 30
Dependent Claim
19 words
A gas discharge tube according to claim 21, characterised in that said lamp is located within said housing (20).
Claim 31
Dependent Claim
47 words
A gas discharge laser comprising; a housing (20) for containing a gaseous laser medium; a means (42) for exciting said gas to create a gas discharge; and a lamp (110) for emitting photons to promote dissociation of said gas to facilitate the creation of said gas discharge.
Claim 32
Dependent Claim
47 words
A gas discharge laser comprising; a housing (20) for containing a gaseous laser medium; a means (42) for exciting said gas to create a gas discharge; and a lamp (110) for emitting photons to promote dissociation of said gas to facilitate the creation of said gas discharge.
Claim 33
Dependent Claim
78 words
An RF excited laser comprising; a pair of elongated, spaced apart elctrodes (120,121); a laser gas disposed between said electrodes (120,122); means for exciting said laser gas to create a gas discharge, said means including a a means (128,124,126) for generating RF energy; and means (132,134) for electrically connecting said excitation means to one of said electrodes (120,122) at more than one location and in a manner such that said RF energy is in phase at said locations.
Claim 34
Dependent Claim
78 words
An RF excited laser comprising; a pair of elongated, spaced apart elctrodes (120,121); a laser gas disposed between said electrodes (120,122); means for exciting said laser gas to create a gas discharge, said means including a a means (128,124,126) for generating RF energy; and means (132,134) for electrically connecting said excitation means to one of said electrodes (120,122) at more than one location and in a manner such that said RF energy is in phase at said locations.
Claim 35
Dependent Claim
28 words
A laser according to claim 25, characterised in that said means for generating RF energy includes at least two amplifiers (124,126) driven by a single RF oscillator (128).
Claim 36
Dependent Claim
29 words
A laser according to claim 26, characterised in that the output of said amplifiers (124,126) is electrically connected to said one electrode (120) through an impedance matching network (132,134).
Claim 37
Independent Claim
41 words
A method of treating tissue comprising the steps of: generating a pulsed laser beam wherein each pulse is shorter than one millisecond and has an energy per pulse greater than 100 millijoules; and delivering said pulsed laser beam to the tissue.
Claim 38
Independent Claim
41 words
A method of treating tissue comprising the steps of: generating a pulsed laser beam wherein each pulse is shorter than one millisecond and has an energy per pulse greater than 100 millijoules; and delivering said pulsed laser beam to the tissue.
Claim 39
Dependent Claim
19 words
A method according to claim 28, characterised in that said pulses are about 0.5 milliseconds or less in duration.
Claim 40
Dependent Claim
18 words
A method according to claim 28, characterised in that said laser beam has a wavelength of 10.6 microns.
Claim 41
Independent Claim
40 words
An apparatus for treating tissue comprising: means for generating a pulsed laser beam wherein each pulse is shorter than one millisecond and has an energy per pulse greater than 100 millijoules; and means for delivering said beam to the tissue.
Claim 42
Independent Claim
40 words
An apparatus for treating tissue comprising: means for generating a pulsed laser beam wherein each pulse is shorter than one millisecond and has an energy per pulse greater than 100 millijoules; and means for delivering said beam to the tissue.
Claim 43
Dependent Claim
24 words
An apparatus according to claim 31, characterised in that said beam generation means generates pulses that are about 0.5 milliseconds or less in duration.
Claim 44
Dependent Claim
18 words
An apparatus according to claim 31, characterised in that said beam generation means includes a C0 2 laser.
References Cited (Backward Citations)
No citation records indexed.
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