# US 2014/0197729 A1 · Plasma light source > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0197729 A1 - Document ID: US20140197729A1 - Status: Published application - Kind: A1 - Application number: 14/125,114 - Filed: 2012-06-28 - Published: 2014-07-17 - Earliest claimed: 2011-07-01 - Inventors: Andrew Simon Neate - Web page: https://patentgrep.com/patent/US20140197729A1 ## CPC - H01J 65/044: {the field being produced by a separate microwave unit} - H01J 9/247: {specially adapted for gas-discharge lamps} - H01J: ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS (spark-gaps H01T; electric arc lamps H05B31/00; particle accelerators H05H) ## Abstract A lucent waveguide plasma light source has a quartz waveguide body with a central through bore. The bore has orifices at its opposite ends, opening centrally of flat, end faces of the body. Between these the body has a circular cylindrical periphery. A drawn quartz tube is inserted into the body. The tube has its one end closed and a collar which locates the tube in the bore and is fused to the faces at the orifices of the bore. The tube is evacuated and charged with excitable material and closed as a sealed void. A Faraday cage and an antenna in a bore in the body are provided for feeding microwave energy to the light source. When powered with microwaves, resonance is established in the wave guide and a plasma is established in the void, wherein Light radiates and leaves the waveguide and Faraday cage radially of the periphery. ## Claims ### Claim 1 A lucent waveguide plasma light source, having: a fabrication of solid-dielectric, lucent material, having; a closed void containing electro-magnetic wave, normally microwave, excitable material; and a Faraday cage: delimiting a waveguide, being at least partially lucent, and normally at least partially transparent, for light emission from it, normally having a non-lucent closure and enclosing the fabrication; provision for introducing plasma exciting electro-magnetic waves, normally microwaves, into the waveguide; the arrangement being such that on introduction of electro-magnetic waves, normally microwaves, of a determined frequency a plasma is established in the void and light is emitted via the Faraday cage, and wherein the fabrication includes: a lucent waveguide body having a bore and a lucent tube in the bore, the tube providing the closed void and the tube having: a first closed end and a second closed end and a fusion between the body and the tube at an orifice of the bore at or close to the first closed end of the tube wherein the void extends at least to the fusion between the body and the tube at the orifice of the bore. ### Claim 2 (depends on 1) A lucent waveguide plasma light source as claimed in claim 1, wherein the tube is formed with a swelling at the fusion between the body and the tube. ### Claim 3 (depends on 1) A lucent waveguide plasma light source as claimed in claim 1, wherein the void extends beyond the fusion and/or the swelling of the tube. ### Claim 4 (depends on 1) A lucent waveguide plasma light source as claimed in claim 1, wherein the second closed end of the tube is free within the bore. ### Claim 5 (depends on 1) A lucent waveguide plasma light source as claimed in claim 1, wherein the tube has a second fusion between the body and the tube at an other orifice of the bore, the bore having been a through-bore. ### Claim 6 (depends on 1) A lucent waveguide plasma light source as claimed in claim 1, wherein the bore in the waveguide body is bored and polished to an internal diameter such as to receive the tube with a sliding fit. ### Claim 7 (depends on 1) A lucent waveguide plasma light source as claimed in claim 1, wherein an annular gap is provided between the bore and the tube. ### Claim 8 (depends on 1) A lucent waveguide plasma light source as claimed in claim 1, wherein the bore is evacuated. ### Claim 9 (depends on 1) A lucent waveguide plasma light source as claimed in claim 1, wherein the bore is filled with inert gas. ### Claim 10 (depends on 1) A lucent waveguide plasma light source as claimed in claim 1, wherein the bore is open at at least one end. ### Claim 11 (depends on 1) A lucent waveguide plasma light source as claimed in claim 1, wherein the lucent waveguide body and the lucent tube are of the same material. ### Claim 12 (depends on 1) A lucent waveguide plasma light source as claimed in claim 1, wherein the lucent waveguide body and the lucent tube are of different materials. ### Claim 13 (depends on 1) A lucent waveguide plasma light source as claimed in claim 1, wherein at least one of the lucent waveguide body and the lucent tube is of quartz. ### Claim 14 A method of making a fabrication for a lucent waveguide plasma light source the method consisting in the steps of: providing the lucent waveguide body with a bore; closing an end of the lucent tube; forming a swelling in the tube at a position to locate the tube with respect to waveguide body; inserting the lucent tube into the bore in the body; fusing the tube to the body at a first orifice of the bore; charging the tube with the excitable material; and closing the other end of the tube to form a void containing an excitable material; wherein the void extends at least to the fusion between the body and the tube at the orifice of the bore. ### Claim 15 (depends on 14) A method of making a lucent waveguide plasma light source as in claim 14, wherein at least one end of the tube is closed before insertion of the tube into in the bore. ### Claim 16 (canceled) ### Claim 17 (depends on 14) A method of making a lucent waveguide plasma light source as claimed in claim 14, further consisting of the step of fusing the tube to the body at a second orifice of the bore. ### Claim 18 (depends on 14) A method of making a lucent waveguide plasma light source as claimed in claim 14, wherein the lucent tube is inserted into the bore and fused to the body of the waveguide at at least the first orifice of the bore prior to charging the tube with the excitable material and closing the tube. ### Claim 19 (depends on 14) A method of making a lucent waveguide plasma light source as claimed in claim 14, wherein the lucent tube is inserted into the bore and fused to the body of the waveguide at at least the first orifice of the bore after charging the tube with the excitable material and closing the tube. ### Claim 20 (depends on 14) A method of making a lucent waveguide plasma light source as claimed in claim 14, further consisting of the steps of: evacuating the bore, and closing the bore. ### Claim 21 (depends on 20) A method of making a lucent waveguide plasma light source as claimed in claim 20, further consisting of the step of filling the bore with an inert gas before closing the bore. ### Claim 22 A fabrication for a lucent waveguide plasma light source of solid-dielectric, lucent material, the fabrication having: a closed void containing electro-magnetic wave, normally microwave, excitable material wherein the fabrication includes: a lucent waveguide body having a bore and a lucent tube in the bore, the tube providing the closed void and the tube having: a first closed end and a second closed end and a fusion between the body and the tube at an orifice of the bore at or close to the first closed end of the tube and wherein the void extends at least to the fusion between the body and the tube at the orifice of the bore.