RF Excited electrodeless gas arc lamp for pumping lasers

Claim 2

An inert gas electrodeless arc lamp adapted to produce sufficient light of appropriate wavelength to pump a laser, comprising: a transparent lamp envelope containing an inert gas from the group consisting of krypton, xenon and argon, the effective width of the lamp envelope being in the range of from about 1 to about 30 mm; the length of the envelope being not more than about 150 mm, and the cold pressure of the gas therein being in the range of from about 0.5 to about 20 atmospheres; a coil around the envelope for the envelope to be in the flux generated by connecting RF voltage through the coil; a source of RF voltage connected in a circuit through the coil, said source being adapted to supply sufficient RF power through the coil to maintain a plasma in the gas in the envelope; means in said circuit for adjusting the impedance of the circuit first to match the impedance of the cold gas in the envelope and then to match the impedance of a plasma ignited in the gas; and means for mounting a laser rod adjacent the lamp envelope for light from the envelope to impinge on a laser rod mounted by said means.

Claim 3

The lamp of claim 1 in which said envelope is an annular compartment having a central bore therethrough and means for mounting a laser rod through said bore.

Claim 4

The lamp combination of claim 1 in which the gas in the lamp envelope is krypton and in which the difference between the outer and inner radii of the annular compartment is in the range of from 1 to about 30 mm. the annular envelope is not more than about 50 mm. long, and the cold pressure of the gas in the envelope is in the range of from 0.5 to about 20 atmospheRes.

Claim 5

The lamp of claim 2 which includes diffuse reflecting means at the periphery of said annular compartment for reflecting back toward the central bore portion of the compartment that light from a laser rod mounted through said bore which reaches said outer periphery.

Claim 6

The lamp of claim 4 in which said reflecting means comprises diffuse reflecting surfaces around the outside of said annular envelope compartment, and circumferentially outside of the coil.

Claim 7

The lamp of claim 4 in which the coil is tightly around the outside surface of the lamp envelope annulus and said reflecting means includes a diffuse reflector outside the coil.

Claim 8

The lamp of claim 4 in which said reflecting means includes the turns of the coil being substantially flat in the direction toward the bore of the annulus, the flat surfaces facing said bore having diffusing reflective surfaces.

Claim 9

The lamp of claim 4 including filter means mounted for filtering out at least a portion of an unwanted component of the light received by the laser rod.

Claim 10

The lamp of claim 4 in which the lamp envelope annulus is axially within a cylindrical chamber, and which includes means for circulating a liquid coolant through the chamber, said coil being around the outside of the chamber.

Claim 11

The lamp of claim 9 in which the cylindrical side wall of the chamber is filter glass, and in which the diffuse reflecting surface is around the outside of said cylindrical side wall of the chamber.

Claim 12

The lamp of claim 1 including means for igniting a plasma in the gas, and variable impedance means in said circuit for adjusting the circuit substantially to resonance for obtaining a high voltage in the circuit before a plasma is ignited therein and then to substantially match the impedance of plasma in the gas.

Claim 13

The lamp of claim 11 in which said impedance adjusting means comprises a pair of capacitors, are in parallel and the other in series with the voltage source and coil.

Claim 14

An inert gas electrodeless arc lamp and a laser rod pumped thereby comprising in combination: a transparent lamp envelope containing an inert gas from the group consisting of krypton, xenon and argon, the effective width of the lamp envelope being in the range of from about 1 to about 30 mm; the length of the envelope being not more than about 50 mm, and the cold pressure of the gas therein being in the range of from about 0.5 to about 20 atmospheres; a coil around the envelope for the envelope to be in the flux generated by connecting RF voltage through the coil; a source of RF voltage connected in a circuit through the coil, said source being adapted to supply sufficient RF power through the coil to maintain a plasma in the gas in the envelope; means in said circuit for adjusting the impedance of the circuit first to match the impedance of the cold gas in the envelope and then to match the impedance of a plasma ignited in the gas; a laser rod mounted adjacent the lamp envelope for light from the envelope to impinge thereon; and reflecting means surrounding the lamp envelope and laser rod for reflecting toward the rod light from the lamp envelope which does not impinge directly on the laser rod and that light from the lamp envelope which is not absorbed by the laser rod.

Claim 15

An inert gas electrodeless arc lamp and a laser rod pumped thereby comprising in combination: a transparent lamp envelope containing an inert gas from the group consisting of krypton, xenon and argon, the effective width of the lamp envelope being in the range of from about 1 to about 30 mm; the length of the envelope being not more than about 50 mm, and the cold pressure of the gas therein being in the range of from about 0.5 to about 20 atmospheres; a coil around the envelope for the envelope to be in the flux generated by connecting RF voltage through the coil; a source of RF voltage connected in a circuit through the coil, said source being adapted to supply sufficient RF power through the coil to maintain a plasma in the gas in the envelope; means in said circuit for adjusting the impedance of the circuit first to match the impedance of the cold gas in the envelope and then to match the impedance of a plasma ignited in the gas; a laser rod mounted adjacent the lamp envelope for light from the envelope to impinge thereon; and reflecting means surrounding the lamp envelope and laser rod for reflecting toward the rod light from the lamp envelope which does not impinge directly on the laser rod and that light from the lamp envelope which is not absorbed by the laser rod.

Claim 16

The combination of claim 13 in which said reflecting means is a generally tubular surface that is elliptical in cross section, in which the lamp envelope is mounted at one of the foci of the elliptical surface, and which includes means for mounting a laser rod axially along the other of said foci.

Claim 17

The combination of claim 13 in which said reflecting means is a spherical reflecting surface enclosing the lamp envelope and laser rod being closely adjacent the center of the sphere.

Claim 18

The combination of claim 13 in which the gas in the envelope is principally krypton and the laser rod is an Nd:YAG laser rod.