# US 8,464,556 B2 · Microstructured optical fibers and methods > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,464,556 B2 - Document ID: US8464556B2 - Status: Granted - Kind: B2 - Application number: 12/151,170 - Filed: 2008-05-05 - Published: 2008-11-13 - Granted: 2013-06-18 - Earliest claimed: 2007-05-08 - Assignees: Corning Incorporated - Applicants: Dana Craig Bookbinder; Robert Brett Desorcie; Mark Alan McDermott; Pushkar Tandon - Inventors: Dana Craig Bookbinder; Robert Brett Desorcie; Mark Alan McDermott; Pushkar Tandon - Web page: https://patentgrep.com/patent/US8464556B2 ## CPC - C03B 37/0142: {Reactant deposition burners} - C03B 37/01446: {Thermal after-treatment of preforms, e.g. dehydrating, consolidating, sintering (C03B37/01853 takes precedence)} - C03B 37/0146: {Furnaces therefor, e.g. muffle tubes, furnace linings} - C03B 37/01466: {Means for changing or stabilising the diameter or form of tubes or rods (C03B37/01861 takes precedence)} - C03B 37/02781: {Hollow fibres, e.g. holey fibres} - C03B 2203/14: Non-solid, i.e. hollow products, e.g. hollow clad or with core-clad interface - C03B 2203/42: Photonic crystal fibres, e.g. fibres using the photonic bandgap PBG effect, microstructured or holey optical fibres - C03B 2205/44: Monotoring or regulating the preform feed rate - C03B 2205/72: Controlling or measuring the draw furnace temperature - C03B: MANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES ## Abstract Method of making a microstructured optical fiber. Silica glass based soot is deposited on a substrate to form at least a portion of an optical fiber preform by traversing a soot deposition burner with respect to said substrate at a burner traverse rate greater than 3 cm/sec, thereby depositing a layer of soot having a thickness less than 20 microns for each of a plurality of burner passes. At least a portion of the soot preform is then consolidated inside a furnace to remove greater than 50 percent of the air trapped in said soot preform, said consolidating taking place in a gaseous atmosphere containing krypton, nitrogen, or mixtures thereof under conditions which are effective to trap a portion of said gaseous atmosphere in said preform during said consolidation step, thereby forming a consolidated preform which when viewed in cross section will exhibit at least 50 voids therein. ## Claims ### Claim 1 A method of making an optical fiber comprising depositing silica glass based soot on a substrate to form at least a portion of an optical fiber preform by traversing a soot deposition burner with respect to said substrate at a burner traverse rate greater than 3 cm/sec, thereby depositing a layer of soot having a thickness less than 20 microns for each of a plurality of burner passes; and consolidating said at least a portion of the soot preform inside a furnace to remove greater than 50 percent of the air trapped in said soot preform, said consolidating taking place in a gaseous atmosphere containing krypton, argon, SO2, or mixtures thereof under conditions which are effective to trap a portion of said gaseous atmosphere in said preform during said consolidation step, thereby forming a consolidated preform which when viewed in cross section will exhibit at least 50 voids therein. ### Claim 2 (depends on 1) The method of claim 1, wherein said preform when viewed in cross section will exhibit at least 10,000 voids therein. ### Claim 3 (depends on 1) The method of claim 1, wherein said consolidating taking place in a gaseous atmosphere further comprising helium. ### Claim 4 (depends on 1) The method of claim 1, wherein said consolidating taking place in a gaseous atmosphere which comprises krypton. ### Claim 5 (depends on 1) The method of claim 1, wherein said soot deposited in said depositing step comprises a portion of the cladding region of the optical fiber preform. ### Claim 6 (depends on 1) The method of claim 1, wherein said burner traverse rate in said depositing step is greater than 7 cm/sec. ### Claim 7 (depends on 6) The method of claim 6, wherein said depositing step comprises depositing a layer of soot having a thickness less than 10 microns for each of a plurality of burner passes. ### Claim 8 (depends on 6) The method of claim 6, wherein said depositing step comprises depositing a layer of soot having a thickness less than 15 microns for each of a plurality of burner passes. ### Claim 9 (depends on 1) The method of claim 1, wherein said burner traverse rate in said depositing step is greater than 10 cm/sec. ### Claim 10 (depends on 1) The method of claim 1, wherein said depositing step comprises depositing a layer of soot having a thickness less than 15 microns for each of a plurality of burner passes. ### Claim 11 (depends on 1) The method of claim 1, further comprising, subsequent to said consolidation step and prior to a step of drawing the preform into an optical fiber, drawing the consolidated preform having voids therein into a cane to thereby reduce the diameter of the consolidated preform having voids therein to a outer preform diameter which is greater than 5 mm, under conditions which are effective to cause said voids to expand in diameter during the redraw step. ### Claim 12 (depends on 11) The method of claim 11, wherein said drawing the preform into cane step comprises drawing said preform at a speed of greater than 5 cm per minute while exposing the preform to a temperature between about 1650-1775° C. ### Claim 13 (depends on 11) The method of claim 11, wherein said drawing the preform into cane step comprises drawing said preform at a speed of greater than 7 cm per minute while exposing the preform to a temperature between about 1650-1775° C. ### Claim 14 (depends on 11) The method of claim 11, further comprising drawing said fiber at a draw tension between 250 and 300 grams. ### Claim 15 (depends on 1) The method of claim 1, further comprising drawing said fiber at a draw tension greater than 200 g. ### Claim 16 (depends on 1) The method of claim 1, further comprising drawing said fiber at a draw tension between 250 and 300 grams.