Radio frequency-excited gas laser

Claim 2

An RF-excited laser system comprising: (a) a longitudinal RF cavity having a cross section perpendicular to the longitudinal axis of said RF cavity which has at least one constricted region which extends along the length of said RF cavity, each said constricted region serving to concentrate transverse electric field lines within each said constricted region for the purpose of supporting a plasma discharge in each said constricted region; (b) reflective means for defining an optical cavity, said optical cavity at least partially occupying the interior of said RF cavity; (c) a gain medium disposed within said optical cavity; and (d) an RF pumping means for applying power to said RF cavity, said longitudinal cavity having an associated longitudinal resonance and at least one transverse resonance, each said transverse resonance having an associated transverse resonant frequency, said RF pumping means providing RF power to said RF cavity, said RF power exciting at least one said transverse resonance thereby maximizing the concentration of said transverse electric field lines within each said constricted region, the opposing surfaces bounding each said constricted region further comprising upper and lower opposing surfaces which have discontinuities along the length of each said constricted region so as to suppress said longitudinal resonance of said RF cavity at its drive frequency, thereby providing uniform RF excitation along the entire length of each said constricted or discharge region.

Claim 3

An RF-excited laser system as recited in claim 1 wherein said discontinuities comprise a set of curvilinear slots, each said slot cut along the length of each said opposing surface bounding each said constricted region.

Claim 4

An RF-excited laser system as recited in claim 2 wherein said discontinuities are spaced periodically along the length of each said constricted region.

Claim 5

An RF-excited laser system as recited in claim 3 wherein said discontinuities comprise slots cut at an angle to the longitudinal axis of said RF cavity partially across said upper and lower opposing surfaces which bound each said constricted region, said slots made by initiating a plurality of cuts in both said upper and lower surfaces bounding each said constricted region commencing from one side of each said constricted region partially across each said constricted region, the side from which said cuts commence alternating between the right side and the left side of each said constricted region at the location of every RF current maximum along the longitudinal axis of said RF cavity, the plurality of said slots in said upper surface bounding each said constricted region displaced to occur at positions which are longitudinally between the plurality of said slots in said lower surface bounding each said constricted region, the slotted upper and lower surfaces bounding each said constricted region thereby forming meandering, but continuous surface paths as a function of longitudinal displacement along said RF cavity, said displacement between the set of slots in said upper surface and the set of slots in said lower surface reducing variation in the electric field along the longitudinal axis of said RF cavity while not substantially affecting the electric field in the direction which is perpendicular to both said longitudinal axis of said RF cavity and the direction of the transverse electric field confined within each said constricted region.

Claim 6

An RF-excited laser system as recited in claim 1 wherein said gain medium is contained within at least one gas enclosure within each said constricted region, said gas enclosure made of a low loss, dielectric material and having integral laser mirrors attached thereto.

Claim 7

An RF-excited laser system as recited in claim 5 wherein the shape of said RF cavity is capable of perturbation so as to shift said transverse resonant frequencies of said RF cavity.

Claim 8

An RF-excited laser system as recited in claim 1 wherein said RF pumping means comprises at least one magnetron.

Claim 9

An RF-excited laser system comprising: (a) a longitudinal RF cavity having a cross section perpendicular to the longitudinal axis of said RF cavity which has multiple expanded regions laterally connected via multiple constricted regions, each said constricted region serving to concentrate transverse electric field lines within each said constricted region for the purpose of supporting a plasma discharge in each said constricted region; (b) reflective means for defining an optical cavity, said optical cavity at least partially occupying the interior of said RF cavity; (c) a gain medium disposed within said optical cavity; and (d) an RF pumping means for applying power to said RF cavity, said longitudinal cavity having an associated longitudinal resonance and at lest one transverse resonance, each said transverse resonance having an associated transverse resonant frequency, said RF pumping means providing RF power to said RF cavity, said RF power exciting at least one said transverse resonance thereby maximizing the concentration of said transverse electric field lines within each said constricted region.

Claim 10

An RF-excited laser system comprising: (a) a longitudinal RF cavity having a cross section perpendicular to the longitudinal axis of said RF cavity which has multiple expanded regions laterally connected via multiple constricted regions, each said constricted region serving to concentrate transverse electric field lines within each said constricted region for the purpose of supporting a plasma discharge in each said constricted region; (b) reflective means for defining an optical cavity, said optical cavity at least partially occupying the interior of said RF cavity; (c) a gain medium disposed within said optical cavity; and (d) an RF pumping means for applying power to said RF cavity, said longitudinal cavity having an associated longitudinal resonance and at lest one transverse resonance, each said transverse resonance having an associated transverse resonant frequency, said RF pumping means providing RF power to said RF cavity, said RF power exciting at least one said transverse resonance thereby maximizing the concentration of said transverse electric field lines within each said constricted region.

Claim 11

An RF-excited laser system as recited in claim 8 wherein said RF pumping means further comprises a plurality of individual RF power sources, each said individual RF power source coupling power into a corresponding said expanded region.

Claim 12

An RF-excited laser system comprising: (a) a longitudinal RF cavity having a cross section perpendicular to the longitudinal axis of said RF cavity which has at least one constricted region which extends along the length of said RF cavity, each said constricted region serving to concentrate transverse electric field lines within each said constricted region for the purpose of supporting a plasma discharge in each said constricted region; (b) reflective means for defining an optical cavity, said optical cavity at least partially occupying the interior of said RF cavity; (c) a gain medium disposed within said optical cavity; and (d) an RF pumping means for applying power to said RF cavity, said longitudinal cavity having an associated longitudinal resonance and at least one transverse resonance, each said transverse resonance having an associated transverse resonant frequency, said RF pumping means providing RF power to said RF cavity, said RF power exciting at least one said transverse resonance thereby maximizing the concentration of said transverse electric field lines within each said constricted region, said RF cavity having defined walls and the shape of said RF cavity capable of perturbation so as to shift said transverse resonant frequencies of said RF cavity.

Claim 13

An RF-excited laser system comprising: (a) a longitudinal RF cavity having a cross section perpendicular to the longitudinal axis of said RF cavity which has at least one constricted region which extends along the length of said RF cavity, each said constricted region serving to concentrate transverse electric field lines within each said constricted region for the purpose of supporting a plasma discharge in each said constricted region; (b) reflective means for defining an optical cavity, said optical cavity at least partially occupying the interior of said RF cavity; (c) a gain medium disposed within said optical cavity; and (d) an RF pumping means for applying power to said RF cavity, said longitudinal cavity having an associated longitudinal resonance and at least one transverse resonance, each said transverse resonance having an associated transverse resonant frequency, said RF pumping means providing RF power to said RF cavity, said RF power exciting at least one said transverse resonance thereby maximizing the concentration of said transverse electric field lines within each said constricted region, said RF cavity having defined walls and the shape of said RF cavity capable of perturbation so as to shift said transverse resonant frequencies of said RF cavity.

Claim 14

An RF-excited laser system as recited in claim 10 wherein said perturbation of shape of said RF cavity is achieved by translation of at least one said wall of said RF cavity, electrical contact maintained with translatable walls via conducting spring fingerstock.

Claim 15

An RF-excited laser system as recited in claim 10 wherein said walls of said RF cavity are flexible and can be deflected by actuation means for the purpose of tuning said transverse resonant frequencies of said RF cavity.

Claim 16

An RF-excited laser system as recited in claim 12 wherein said laser system includes electrically controllable actuation means for tuning said transverse resonant frequencies of said RF cavity, an electric field sensor disposed within said RF cavity, and control means receiving field strength measurements from said electric field sensor and transmitting to said actuation means a control signal for tuning of said RF cavity, the combination of said actuation means, electric field sensor, and control means providing closed-loop feedback control of cavity tuning to maintain relatively constant RF excitation of said RF cavity despite the influence of thermal variations, vibration, and motion of said RF cavity which tend to detune said RF cavity.

Claim 17

An RF-excited laser system comprising: (a) a longitudinal RF cavity having an associated longitudinal resonance supporting a discharge region between opposing surfaces of electrodes contained within said RF cavity, said electrode surfaces having discontinuities along the length of said discharge region so as to suppress said longitudinal resonance of said RF cavity at its drive frequency, thereby providing uniform RF excitation along the entire length of said discharge region; (b) reflective means for defining an optical cavity, said optical cavity at least partially occupying the interior of said RF cavity; (c) a gain medium disposed within said optical cavity; and (d) an RF pumping means for applying power to said RF cavity.

Claim 18

An RF-excited laser system comprising: (a) a longitudinal RF cavity having an associated longitudinal resonance supporting a discharge region between opposing surfaces of electrodes contained within said RF cavity, said electrode surfaces having discontinuities along the length of said discharge region so as to suppress said longitudinal resonance of said RF cavity at its drive frequency, thereby providing uniform RF excitation along the entire length of said discharge region; (b) reflective means for defining an optical cavity, said optical cavity at least partially occupying the interior of said RF cavity; (c) a gain medium disposed within said optical cavity; and (d) an RF pumping means for applying power to said RF cavity.

Claim 19

An RF-excited laser system as recited in claim 14 wherein said gain medium is contained within at least one gas enclosure positioned between said opposing electrode surfaces, said gas enclosure made of a low loss, dielectric material and having integral laser mirrors attached thereto.

Claim 20

An RF-excited laser system as recited in claim 15 wherein said gain medium is contained within a plurality of said gas enclosures placed parallel to one another between said opposing electrode surfaces.

Claim 21

An RF-excited laser system comprising: (a) RF modules, each comprising a longitudinal RF cavity, said longitudinal RF cavity having a cross section perpendicular to the longitudinal axis of said RF cavity which has at least one constricted region which extends along the length of said RF cavity, said longitudinal cavity having an associated longitudinal resonance and at least one transverse resonance, each said constricted region serving to concentrate transverse electric field lines within each said constricted region for the purpose of supporting a plasma discharge in each said constricted region, a gain medium disposed within at least a portion of said RF cavity, and RF pumping means for applying power to said RF cavity; (b) a modular assembly comprising a longitudinal mounting platform for support of said RF modules, said modular assembly accommodating a multiplicity of said RF modules interconnected end-to-end in serial fashion; (c) reflective means for defining a composite optical cavity for said RF-excited laser system, said optical cavity largely encompassing the optical gain volumes of each said RF module when placed end-to-end; and (d) optical coupling means allowing the propagation of light from one said RF module to another such said RF module, and to said reflective means, said optical coupling means prohibiting the transfer of RF energy among said RF modules.

Claim 22

An RF-excited laser system comprising: (a) RF modules, each comprising a longitudinal RF cavity, said longitudinal RF cavity having a cross section perpendicular to the longitudinal axis of said RF cavity which has at least one constricted region which extends along the length of said RF cavity, said longitudinal cavity having an associated longitudinal resonance and at least one transverse resonance, each said constricted region serving to concentrate transverse electric field lines within each said constricted region for the purpose of supporting a plasma discharge in each said constricted region, a gain medium disposed within at least a portion of said RF cavity, and RF pumping means for applying power to said RF cavity; (b) a modular assembly comprising a longitudinal mounting platform for support of said RF modules, said modular assembly accommodating a multiplicity of said RF modules interconnected end-to-end in serial fashion; (c) reflective means for defining a composite optical cavity for said RF-excited laser system, said optical cavity largely encompassing the optical gain volumes of each said RF module when placed end-to-end; and (d) optical coupling means allowing the propagation of light from one said RF module to another such said RF module, and to said reflective means, said optical coupling means prohibiting the transfer of RF energy among said RF modules.

Claim 23

An RF-excited laser system as recited in claim 17 wherein the supplied RF energy excites at least one said transverse resonance thereby maximizing the concentration of said transverse electric field lines within each said constricted region, each said constricted region bounded by opposing surfaces of electrodes contained with said RF cavity, each said transverse resonance having an associated transverse resonant frequency.

Claim 24

An RF-excited laser system as recited in claim 18 wherein said optical coupling means comprises aperture coupling.

Claim 25

An RF-excited laser system as recited in claim 18 wherein said optical coupling means comprises a waveguide beyond cutoff.

Claim 26

An RF-excited laser system as recited in claim 18 wherein said optical coupling means comprises a microwave choke.

Claim 27

An RF-excited laser system as recited in claim 18 wherein said cross section is the shape of a letter "H" foreshortened in height, the horizontal constricted region of the "H"-shaped cross section comprising said constricted region which concentrates said RF energy.

Claim 28

An RF-excited laser system as recited in claim 18 wherein said cavity cross section comprises multiple expanded regions laterally connected via multiple said constricted regions.

Claim 29

An RF-excited laser system as recited in claim 18 wherein said RF cavity has defined walls and the shape of said RF cavity can be perturbed so as to shift said transverse resonant frequencies of said RF cavity.

Claim 30

An RF-excited laser system as recited in claim 24 wherein said perturbation of shape of said RF cavity is achieved by translation of at least one said wall of said RF cavity, electrical contact maintained with translatable walls via conducting spring fingerstock.

Claim 31

An RF-excited laser system as recited in claim 24 wherein said walls of said RF cavity are flexible and capable of deflection by actuation means for the purpose of tuning said RF cavity.

Claim 32

An RF-excited laser system as recited in claim 26 wherein said laser system includes electrically controllable actuation means for tuning said transverse resonant frequencies of said RF cavity, an electric field sensor disposed within said RF cavity, and control means receiving field strength measurements from said electric field sensor and transmitting to said actuation means a control signal for tuning of said cavity, the combination of said actuation means, electric field sensor, and control means providing closed-loop feedback control of cavity tuning to maintain relatively constant RF excitation of said RF cavity despite the influence of thermal variations, vibration, and motion of said RF cavity which tend to detune said RF cavity.

Claim 33

An RF-excited laser system as recited in claim 18 wherein said gain medium is contained within at least one gas enclosure within each said constricted region, said gas enclosure made of a low loss, dielectric material and having integral laser windows attached thereto.

Claim 34

An RF-excited laser system as recited in claim 28 wherein the shape of said RF cavity can be perturbed so as to shift said transverse resonant frequencies of said RF cavity.

Claim 35

An RF-excited laser system as recited in claim 18 wherein said opposing surfaces bounding each said constricted region further comprise upper and lower opposing surfaces which have discontinuities along the length of each said constricted region so as to suppress said longitudinal resonance of said RF cavity at its drive frequency, thereby providing uniform RF excitation along the entire length of each said constricted or discharge region.

Claim 36

An RF-excited laser system as recited in claim 30 wherein said discontinuities comprise a set of curvilinear slots, each said slot cut along the length of each said opposing surface bounding each said constricted region.

Claim 37

An RF-excited laser system as recited in claim 30 wherein said discontinuities are spaced periodically along the length of each said constricted region.

Claim 38

An RF-excited laser system as recited in claim 32 wherein said discontinuities comprise slots cut at an angle to said longitudinal axis of said RF cavity partially across said upper and lower opposing surfaces which bound each said constricted region, said slots made by initiating cuts in both said upper and lower surfaces bounding each said constricted region commencing from one side of each said constricted region partially across each said constricted region, the side from which said cuts commence alternating between the right side and the left side of each said constricted region at the location of current maxima along the longitudinal axis of said RF cavity, the plurality of said slots in said upper surface bounding each said constricted region displaced to occur at positions which are longitudinally between the set of said slots in said lower surface bounding each said constricted region, the slotted upper and lower surfaces bounding each said constricted region thereby forming meandering, but continuous surface paths as a function of longitudinal displacement along said RF cavity.

Claim 39

An RF-excited laser system as recited in claim 30 wherein said gain medium is contained within at east one gas enclosure within said constricted region, said gas enclosure made of a lower loss, dielectric material and having integral laser windows attached thereto.

Claim 40

An RF-excited laser system as recited in claim 34 wherein the shape of said RF cavity is capable of perturbation so as to shift said transverse resonant frequencies of said RF cavity.

Claim 41

An RF-excited laser system comprising: (a) RF modules, each comprising a longitudinal RF cavity having an associated longitudinal resonance, a gain medium disposed within at least a portion of said RF cavity, and RF pumping means for applying power to said RF cavity, said RF cavity supporting a discharge region between opposing surfaces of electrodes contained within said RF cavity, said electrode surfaces having discontinuities along the length of said discharge region so as to suppress said longitudinal resonance of said RF cavity at its drive frequency, thereby providing uniform RF excitation along the entire length of said discharge region; (b) a modular assembly comprising a longitudinal mounting platform for support of said RF modules, said modular assembly accommodating a multiplicity of said RF modules interconnected end-to-end in serial fashion; (c) reflective means for defining a composite optical cavity for said RF-excited laser system, said optical cavity largely encompassing the optical gain volumes of each said RF module when placed end-to-end; and (d) optical coupling means allowing the propagation of light from one said RF module to another such said RF module, and to said reflective means, said optical coupling means prohibiting the transfer of RF energy among said RF modules.

Claim 42

An RF-excited laser system comprising: (a) RF modules, each comprising a longitudinal RF cavity having an associated longitudinal resonance, a gain medium disposed within at least a portion of said RF cavity, and RF pumping means for applying power to said RF cavity, said RF cavity supporting a discharge region between opposing surfaces of electrodes contained within said RF cavity, said electrode surfaces having discontinuities along the length of said discharge region so as to suppress said longitudinal resonance of said RF cavity at its drive frequency, thereby providing uniform RF excitation along the entire length of said discharge region; (b) a modular assembly comprising a longitudinal mounting platform for support of said RF modules, said modular assembly accommodating a multiplicity of said RF modules interconnected end-to-end in serial fashion; (c) reflective means for defining a composite optical cavity for said RF-excited laser system, said optical cavity largely encompassing the optical gain volumes of each said RF module when placed end-to-end; and (d) optical coupling means allowing the propagation of light from one said RF module to another such said RF module, and to said reflective means, said optical coupling means prohibiting the transfer of RF energy among said RF modules.

Claim 43

An RF-excited laser system as recited in claim 36 wherein said gain medium is contained within at least one gas enclosure positioned between said opposing electrode surfaces, said gas enclosure made of a low loss, dielectric material and having integral laser mirrors attached thereto.

Claim 44

An RF-excited laser system as recited in claim 37 wherein said gain medium is contained within a plurality of said gas enclosures placed parallel to one another between said opposing electrode surfaces.

Claim 45

An RF-excited laser system comprising: (a) RF modules, each comprising a longitudinal RF cavity, a gain medium disposed within at least a portion of said RF cavity, said gain medium contained within at least one gas enclosure positioned between opposing electrode surfaces within said RF cavity, said gas enclosure made of a low loss, dielectric material and having integral laser windows attached thereto and RF pumping means for applying power to said RF cavity, said RF cavity supporting a discharge region between opposing surfaces of electrodes contained within said RF cavity; (b) a modular assembly comprising a longitudinal mounting platform for support of said RF modules, said modular assembly accommodating a multiplicity of said RF modules interconnected end-to-end in serial fashion; (c) reflective means for defining a composite optical cavity for said RF-excited laser system, said optical cavity largely encompassing the optical gain volumes of each said RF module when placed end-to-end; and (d) optical coupling means allowing the propagation of light from one said RF module to another such said RF module, and to said reflective means, said optical coupling means prohibiting the transfer of RF energy among said RF modules.

Claim 46

An RF-excited laser system comprising: (a) RF modules, each comprising a longitudinal RF cavity, a gain medium disposed within at least a portion of said RF cavity, said gain medium contained within at least one gas enclosure positioned between opposing electrode surfaces within said RF cavity, said gas enclosure made of a low loss, dielectric material and having integral laser windows attached thereto and RF pumping means for applying power to said RF cavity, said RF cavity supporting a discharge region between opposing surfaces of electrodes contained within said RF cavity; (b) a modular assembly comprising a longitudinal mounting platform for support of said RF modules, said modular assembly accommodating a multiplicity of said RF modules interconnected end-to-end in serial fashion; (c) reflective means for defining a composite optical cavity for said RF-excited laser system, said optical cavity largely encompassing the optical gain volumes of each said RF module when placed end-to-end; and (d) optical coupling means allowing the propagation of light from one said RF module to another such said RF module, and to said reflective means, said optical coupling means prohibiting the transfer of RF energy among said RF modules.

Claim 47

An RF-excited laser system comprising: (a) a modular assembly comprising a multiplicity of RF modules interconnected end-to-end in serial fashion, each said RF module further comprising a longitudinal RF cavity, a gain medium disposed within at least a portion of said RF cavity, and RF pumping means for applying power to said RF cavity, said longitudinal RF cavity having a cross section perpendicular to the longitudinal axis of said RF cavity which has at least one constricted region which extends along the length of said RF cavity, each said constricted region serving to concentrate transverse electric field lines within each said constricted region from the purpose of supporting a plasma discharge in each said constricted region, said longitudinal cavity having an associated longitudinal resonance and at least one transverse resonance, each said constricted region bounded by opposing surfaces of electrodes contained with said RF cavity, said opposing surfaces of each said constricted region having discontinuities spaced periodically along the length of said each said constricted region so as to suppress said longitudinal resonance of said RF cavity at its lowest order transverse drive frequency, thereby providing uniform RF excitation along the entire length of each said constricted region, said RF modules interconnected so as to exchange optical energy among said RF modules and prohibit the exchange of RF energy among said RF modules; (b) reflective means for defining a composite optical cavity for said RF-excited laser system, said optical cavity largely encompassing the optical gain volumes of each said RF module when placed end-to-end, said reflective means attached to the ends of said RF modules; and (c) optical coupling means allowing the propagation of light from one said RF module to another such said RF module, and to said reflective means, said optical coupling means prohibiting the transfer of RF energy among said RF modules.

Claim 48

An RF-excited laser system comprising: (a) a modular assembly comprising a multiplicity of RF modules interconnected end-to-end in serial fashion, each said RF module further comprising a longitudinal RF cavity, a gain medium disposed within at least a portion of said RF cavity, and RF pumping means for applying power to said RF cavity, said longitudinal RF cavity having a cross section perpendicular to the longitudinal axis of said RF cavity which has at least one constricted region which extends along the length of said RF cavity, each said constricted region serving to concentrate transverse electric field lines within each said constricted region from the purpose of supporting a plasma discharge in each said constricted region, said longitudinal cavity having an associated longitudinal resonance and at least one transverse resonance, each said constricted region bounded by opposing surfaces of electrodes contained with said RF cavity, said opposing surfaces of each said constricted region having discontinuities spaced periodically along the length of said each said constricted region so as to suppress said longitudinal resonance of said RF cavity at its lowest order transverse drive frequency, thereby providing uniform RF excitation along the entire length of each said constricted region, said RF modules interconnected so as to exchange optical energy among said RF modules and prohibit the exchange of RF energy among said RF modules; (b) reflective means for defining a composite optical cavity for said RF-excited laser system, said optical cavity largely encompassing the optical gain volumes of each said RF module when placed end-to-end, said reflective means attached to the ends of said RF modules; and (c) optical coupling means allowing the propagation of light from one said RF module to another such said RF module, and to said reflective means, said optical coupling means prohibiting the transfer of RF energy among said RF modules.