# US 10,501,361 B2 · Optical fiber preform manufacturing method and optical fiber preform manufacturing device > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,501,361 B2 - Document ID: US10501361B2 - Status: Granted - Kind: B2 - Application number: 13/006,311 - Filed: 2011-01-13 - Published: 2011-05-12 - Granted: 2019-12-10 - Earliest claimed: 2008-07-18 - Assignees: Shin-Etsu Chemical Co., Ltd. - Applicants: Dai Inoue; Takaaki Nagao; Hiroyuki Koide - Inventors: Dai Inoue; Takaaki Nagao; Hiroyuki Koide - Web page: https://patentgrep.com/patent/US10501361B2 ## CPC - C03B 37/01413: {Reactant delivery systems (C03B37/01807 takes precedence; devices therefor in general B01D1/00, B01J4/00)} - C03B 37/014: made entirely or partially by chemical means {, e.g. vapour phase deposition of bulk porous glass either by outside vapour deposition [OVD], or by outside vapour phase oxidation [OVPO] or by vapour axial deposition [VAD] (C03C17/02 takes precedence)} - C03B 2201/31: doped with germanium - C03B 2207/70: Control measures - Y02P 40/57: Improving the yield, e-g- reduction of reject rates - C03B: MANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES - Y02P: CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS ## Abstract An optical fiber base material manufacturing method includes: supplying oxygen, hydrogen, and silicide to a core deposition burner; depositing silicon dioxide; adjusting a drawing up speed so that a deposition tip position remains at the same position in accordance with growth of a porous base material; calculating an average of the drawing up speed at each preset time interval; calculating a difference of the calculated average from a preset value of the drawing up speed; correcting a flow rate of silicon tetrachloride when the supplied hydrogen is hydrogen produced or stored at normal temperature, and correcting a flow rate of hydrogen when the supplied hydrogen is hydrogen obtained by vaporizing liquid hydrogen, where when correcting the flow rate of hydrogen, a flow rate of hydrogen supplied to a cladding deposition burner is also corrected in a ratio of before and after the correction of the flow rate of the hydrogen. ## Claims ### Claim 1 An optical fiber base material manufacturing method for depositing glass particles on a tip of a starting material drawn up while being rotated in a VAD method, the optical fiber base material manufacturing method comprising: supplying oxygen and silicide to a core deposition burner; supplying a first hydrogen having a ratio of orthohydrogen to parahydrogen of 3:1 or supplying a second hydrogen having a ratio of orthohydrogen to parahydrogen that is different from the ratio of the first hydrogen to the core deposition burner; depositing, on the tip of the starting material, silicon dioxide generated in an oxyhydrogen flame by hydrolysis; adjusting a drawing up speed so that a deposition tip position remains at the same position in accordance with growth of a porous base material; calculating an average of the drawing up speed at each of a plurality of time intervals; calculating a difference between i) the calculated average at a time interval from among the plurality of time intervals and ii) a preset value of the drawing up speed; during said supplying the first hydrogen, changing a flow rate of the silicide supplied to the core deposition burner in proportion to the difference; and during said supplying the second hydrogen, changing a flow rate of the second hydrogen supplied to the core deposition burner in proportion to the difference and changing a flow rate of the second hydrogen supplied to a cladding deposition burner in proportion to the difference. ### Claim 2 (depends on 1) The optical fiber base material manufacturing method according to claim 1, wherein a germanium compound is added to the core deposition burner as an additive. ### Claim 3 (depends on 2) The optical fiber base material manufacturing method according to claim 2, wherein the germanium compound is obtained by heating, to be vaporized, germanium tetrachloride to a temperature that is the same as or higher than a boiling point. ### Claim 4 (depends on 1) The optical fiber base material manufacturing method according to claim 1, wherein the silicide is obtained by heating, to be vaporized, silicon tetrachloride to a temperature that is the same as or higher than a boiling point. ### Claim 5 (depends on 1) The optical fiber base material manufacturing method according to claim 1, further comprising: during said supplying the first hydrogen, supplying the first hydrogen to the cladding deposition burner; and during said supplying the second hydrogen, supplying the second hydrogen to the cladding deposition burner. ### Claim 6 (depends on 5) The optical fiber base material manufacturing method according to claim 5, wherein the flow rates of the hydrogen supplied to both the core deposition burner and the cladding deposition burner are controlled by a flow rate control apparatus having a measurement principle based on thermal capacity measurement of gas. ### Claim 7 (depends on 6) The optical fiber base material manufacturing method according to claim 6, wherein the flow rate control apparatus whose measurement principle is based on thermal capacity measurement of gas is a mass flow controller. ### Claim 8 An optical fiber base material manufacturing method for depositing glass particles on a tip of a starting material drawn up while being rotated in a VAD method, the optical fiber base material manufacturing method comprising: storing a first hydrogen having a ratio of orthohydrogen to parahydrogen of 3:1; storing a second hydrogen having a ratio of orthohydrogen to parahydrogen that is different from the ratio of the first hydrogen; vaporizing the second hydrogen; supplying the first hydrogen or supplying the second hydrogen to a core deposition burner via a hydrogen supply source switch; supplying oxygen to the core deposition burner; supplying silicide to the core deposition burner; depositing, on the tip of the starting material, silicon dioxide generated in an oxyhydrogen flame by means of hydrolysis; adjusting a drawing up speed so that a deposition tip position remains at the same position in accordance with growth of a porous base material; calculating an average of the drawing up speed at each of a plurality of time intervals; calculating a difference between i) the calculated average at a time interval from among the plurality of time intervals and ii) a preset value of the drawing up speed; switching the hydrogen supply source switch to be in a first state in which the first hydrogen is supplied to the core deposition burner; while the hydrogen supply source switch is in the first state, changing a flow rate of the silicide supplied to the core deposition burner in proportion to the difference; switching the hydrogen supply source switch to be in a second state in which the second hydrogen is supplied to the core deposition burner; and while the hydrogen supply source switch is in the second state, changing a flow rate of the second hydrogen supplied to the core deposition burner in proportion to the difference and changing a flow rate of hydrogen supplied to a cladding deposition burner in proportion to the difference. ### Claim 9 (depends on 8) The optical fiber base material manufacturing method according to claim 8, wherein a germanium compound is added to the core deposition burner as an additive. ### Claim 10 (depends on 9) The optical fiber base material manufacturing method according to claim 9, wherein the germanium compound is obtained by heating, to be vaporized, germanium tetrachloride to a temperature that is the same as or higher than a boiling point. ### Claim 11 (depends on 8) The optical fiber base material manufacturing method according to claim 8, wherein the silicide is obtained by heating, to be vaporized, silicon tetrachloride to a temperature that is the same as or higher than a boiling point. ### Claim 12 (depends on 8) The optical fiber base material manufacturing method according to claim 8, further comprising: while the hydrogen supply source switch is in the first state, supplying the first hydrogen to the cladding deposition burner; and while the hydrogen supply source switch is in the second state, supplying the second hydrogen to the cladding deposition burner. ### Claim 13 (depends on 12) The optical fiber base material manufacturing method according to claim 12, wherein the flow rates of the hydrogen supplied to both the core deposition burner and the cladding deposition burner are controlled by a flow rate control apparatus having a measurement principle based on thermal capacity measurement of gas. ### Claim 14 (depends on 13) The optical fiber base material manufacturing method according to claim 13, wherein the flow rate control apparatus whose measurement principle is based on thermal capacity measurement of gas is a mass flow controller. ### Claim 15 An optical fiber base material manufacturing method for depositing glass particles on a tip of a starting material drawn up while being rotated in a VAD method, the optical fiber base material manufacturing method comprising: supplying oxygen, hydrogen, and silicide to a core deposition burner, the hydrogen supplied from a first hydrogen source having a ratio of orthohydrogen to parahydrogen of 3:1; depositing, on the tip of the starting material, silicon dioxide generated in an oxyhydrogen flame by means of hydrolysis; adjusting a drawing up speed so that a deposition tip position remains at the same position in accordance with growth of a porous base material; calculating an average of the drawing up speed at each of a plurality of time intervals; calculating a difference between i) the calculated average at a time interval from among the plurality of time intervals and ii) a preset value of the drawing up speed; changing a flow rate of the silicide supplied to the core deposition burner in proportion to the difference; switching from the first hydrogen source to a second hydrogen source having a ratio of orthohydrogen to parahydrogen that is different from the ratio of the first hydrogen source; and changing a flow rate of the hydrogen supplied to the core deposition burner from the second hydrogen source in proportion to the difference and changing a flow rate of hydrogen supplied to a cladding deposition burner from the second hydrogen source in proportion to the difference. ### Claim 16 (depends on 15) The optical fiber base material manufacturing method according to claim 15, wherein a germanium compound is added to the core deposition burner as an additive. ### Claim 17 (depends on 16) The optical fiber base material manufacturing method according to claim 16, wherein the germanium compound is obtained by heating, to be vaporized, germanium tetrachloride to a temperature that is the same as or higher than a boiling point. ### Claim 18 (depends on 15) The optical fiber base material manufacturing method according to claim 15, wherein the silicide is obtained by heating, to be vaporized, silicon tetrachloride to a temperature that is the same as or higher than a boiling point. ### Claim 19 (depends on 15) The optical fiber base material manufacturing method according to claim 15, wherein the flow rates of the hydrogen both supplied to the core deposition burner and the cladding deposition burner are controlled by a flow rate control apparatus having a measurement principle based on thermal capacity measurement of gas. ### Claim 20 (depends on 19) The optical fiber base material manufacturing method according to claim 19, wherein the flow rate control apparatus whose measurement principle is based on thermal capacity measurement of gas is a mass flow controller.