Patent US4778500A successfully refreshed from Google Patents.
US4778500A
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Laser initiated chain reactions for producing a sintered product
Assignee: Research Foundation of City University of New York
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Filing: 1987-08-11
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Granted: 1988-10-18
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Expires: 2007-08-11
Abstract
Abstract A laser initiated process generates a shock wave of sufficient strength to produce a sintered product. The sintered product is prepared from at least a fuel and an oxidizer that will sustain an explosion in a reaction vessel. The explosion is initiated by introducing a laser beam into the reaction vessel and a shock wave begins to propagate at the point where the explosion is initiated. A sintered product is prepared when the shock wave is sufficiently strong to densify the product. Although the reaction will proceed using a two-component fuel-oxidizer mixture, the reaction is especially useful for producing sintered doped or undoped silicon dioxide (SiO2) from a reaction mixture containing at least silicon tetrachloride, hydrogen and oxygen. The sintered SiO2 can be deposited on a deposition surface situated in the reaction vessel to produce a preform that can be processed to produce an optical fiber.
Inventors
- 👤 Avigdor M. Ronn
- 👤 Jaime Nieman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 10:02
CPC Classifications
C; C03; C03B; C03B19/00; C03B19/10; C03B19/1005; C03B19/106; B; B01; B01J; B01J3/00; B01J3/06; B01J3/08; C03B19/14; C03B19/1415; C03B37/00; C03B37/01; C03B37/012; C03B37/014; C03B37/01413; C04; C04B; C04B35/00; C04B35/01; C04B35/14; C04B35/622; C04B35/64; C04B35/645; C06; C06B; C06B43/00; C03B2201/00; C03B2201/06; C03B2201/08; C03B2201/12
Claims Analysis
Total Claims: 31
Claim 1
Independent Claim
101 words
A process for producing sintered products comprising the steps of introducing a mixture of at least one fuel and at least one oxidizer into a reaction vessel at predetermined pressures such that the fuel and oxidizer are capable of sustaining a chain reaction and providing a sintered product, providing a deposition surface within the reaction vessel, and initiating a chain reaction at at least one initiation point in the reaction vessel by irradiating the mixture with at least one laser pulse of sufficient fluence to create a shock wave having sufficient energy to provide a densified product on the deposition surface.
Claim 2
Dependent Claim
101 words
A process for producing sintered products comprising the steps of introducing a mixture of at least one fuel and at least one oxidizer into a reaction vessel at predetermined pressures such that the fuel and oxidizer are capable of sustaining a chain reaction and providing a sintered product, providing a deposition surface within the reaction vessel, and initiating a chain reaction at at least one initiation point in the reaction vessel by irradiating the mixture with at least one laser pulse of sufficient fluence to create a shock wave having sufficient energy to provide a densified product on the deposition surface.
Claim 3
Dependent Claim
27 words
The process of claim 1, wherein the reaction is initiated using a single pulse of a laser selected from Excimer, neodymium:Yag, neodymium:glass, Gallium-Aluminum-Arsenide and CO 2 .
Claim 4
Dependent Claim
21 words
The process of claim 1, wherein the fuel and oxidizer have a vapor pressure at temperatures greater than about -100° C.
Claim 5
Dependent Claim
12 words
The process of claim 3, wherein the fuel and oxidizer are gaseous.
Claim 6
Dependent Claim
14 words
The process of claim 1, wherein the mixture further includes at least one reactant.
Claim 7
Dependent Claim
14 words
The process of claim 5, wherein the mixture includes at least hydrogen and oxygen.
Claim 8
Dependent Claim
11 words
The process of claim 5, wherein the reactant is silicon tetrachloride.
Claim 9
Dependent Claim
13 words
The process of claim 2, wherein the laser is a CO 2 laser.
Claim 10
Dependent Claim
13 words
The process of claim 1, wherein the deposition surface is a seed rod.
Claim 11
Dependent Claim
14 words
The process of claim 5, wherein the at least one reactant is a liquid.
Claim 12
Dependent Claim
18 words
The process of claim 1, wherein the at least one initiation point is more than one initiation point.
Claim 13
Dependent Claim
23 words
The process of claim 11, wherein the chain reaction is initiated at more than one initiation point using more than one laser pulse.
Claim 14
Dependent Claim
23 words
The process of claim 11, wherein the chain reaction is initiated at more than one initiation point using a single divided laser pulse.
Claim 15
Dependent Claim
23 words
The process of claim 1, wherein the sintered product is doped by including a suitable amount of a dopant-containing compound in the mixture.
Claim 16
Dependent Claim
18 words
The process of claim 1, wherein the process is used to form a preform for an optical waveguide.
Claim 17
Dependent Claim
55 words
A process for producing sintered silicon dioxide comprising the steps of introducing a mixture of silicon tetrachloride, hydrogen and oxygen into a cylindrical reaction vessel at a total pressure of over about 1 atmosphere and initiating a reaction in the reaction vessel by irradiating the mixture with a single pulse from a CO 2 laser.
Claim 18
Dependent Claim
55 words
A process for producing sintered silicon dioxide comprising the steps of introducing a mixture of silicon tetrachloride, hydrogen and oxygen into a cylindrical reaction vessel at a total pressure of over about 1 atmosphere and initiating a reaction in the reaction vessel by irradiating the mixture with a single pulse from a CO 2 laser.
Claim 19
Dependent Claim
29 words
The process of claim 16, wherein the sintered silicon dioxide is deposited on a seed rod contained within the reaction vessel to form a preform for an optical waveguide.
Claim 20
Dependent Claim
11 words
The process of claim 17, wherein the seed rod is quartz.
Claim 21
Dependent Claim
12 words
The process of claim 18, wherein the seed rod is doped quartz.
Claim 22
Dependent Claim
26 words
The process of claim 16, wherein the sintered silicon dioxide is doped by introducing a gaseous dopant into the reaction vessel prior to initiating the reaction.
Claim 23
Dependent Claim
26 words
The process of claim 18, wherein the sintered silicon dioxide is doped by introducing a gaseous dopant into the reaction vessel prior to intiating the reaction.
Claim 24
Dependent Claim
16 words
The process of claim 21, wherein the process is used to form a graded index fiber.
Claim 25
Dependent Claim
42 words
The method of claim 17, further including introducing a suitable amount of a dopant-containing reactant into the reaction vessel prior to irradiating the laser beam so as to form doped sintered silicon dioxide on the seed rod after the reaction is initiated.
Claim 26
Dependent Claim
28 words
The process of claim 16, wherein a tube is provided in the reaction vessel and the sintered silicon dioxide is deposited on the inner surface of the tube.
Claim 27
Dependent Claim
10 words
The process of claim 24, wherein the tube is quartz.
Claim 28
Dependent Claim
11 words
The process of claim 24, wherein the tube is doped quartz.
Claim 29
Independent Claim
77 words
A method for producing preforms for optical waveguides comprising: providing a reaction vessel having a deposition surface therein; introducing silicon tetrachloride, hydrogen and oxygen into the reaction vessel at a total pressure of over about 1 atmosphere; and irradiating a laser beam into the reaction vessel at a fluence sufficient to initiate a chain reaction in the vessel and deposit sintered silicon dioxide on the deposition surface to form a preform for an optical fiber or waveguide.
Claim 30
Independent Claim
77 words
A method for producing preforms for optical waveguides comprising: providing a reaction vessel having a deposition surface therein; introducing silicon tetrachloride, hydrogen and oxygen into the reaction vessel at a total pressure of over about 1 atmosphere; and irradiating a laser beam into the reaction vessel at a fluence sufficient to initiate a chain reaction in the vessel and deposit sintered silicon dioxide on the deposition surface to form a preform for an optical fiber or waveguide.
Claim 31
Dependent Claim
41 words
The method of claim 27, further including introducing a suitable amount of dopant-containing reactant into the reaction vessel prior to irradiating the laser beam so as to form doped sintered silicon dioxide on the deposition surface after the reaction is initiated.
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| 3.5 Years (Year 4) | 1991-10-18 | 1992-04-18 | 1992-10-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-10-18 | 1996-04-18 | 1996-10-18 | $3760.00 | Window Closed / Lapsed |
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