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US 6,428,307 B1Granted
Laser ignition
AssigneeThe Regents of the University of California
InventorsJames W. Early, Charles S. Lester
Life of this patent
Estimating the term…
Abstract
In the apparatus of the invention, a first excitation laser or other excitation light source is used in tandem with an ignitor laser to provide a compact, durable, engine deployable fuel ignition laser system. The beam from the excitation light source is split with a portion of it going to the ignitor laser and a second portion of it being recombined with the first portion after a delay before injection into the ignitor laser. Reliable fuel ignition is provided over a wide range of fuel conditions by using a single remote excitation light source for one or more small lasers located proximate to one or more fuel combustion zones.
Claims72
An ignition apparatus comprising:
- (a) an excitation light source;
- (b) a beam splitter positioned to receive output from said excitation light source;
- (c) a first end of a first optical fiber positioned to collect a first portion of a beam from said beam splitter;
- (d) a second end of said first optical fiber positioned to deliver said first portion of said beam into a beam combiner;
- (e) a first end of a second, longer optical fiber positioned to collect a second portion of a beam from said beam splitter;
- (f) a second end of said second optical fiber positioned to deliver a second portion of said beam from said beam splitter into said beam combiner;
- (g) an optical fiber connecting said beam combiner to an ignitor laser so as to transport combined beam output from said beam combiner to said ignitor laser;
- and
- (h) a lens to direct output from said ignitor laser into a combustible fuel.
6 more elements
An ignition apparatus comprising:
- (a) an excitation light source;
- (b) a multiplexing device positioned to receive output from said excitation light source and direct said output from said excitation light source laser into a plurality of beam splitters;
- (c) a plurality of pairs of a first optical fiber and a second optical fiber having first ends positioned to receive, respectively, a first and second portion of a beam from each of said beam splitters;
- (d) wherein said second optical fiber of each pair is longer than said first optical fiber of each pair;
- (e) a second end of each of said first optical fibers positioned to deliver said first portion of said beam from each said beam splitter into a beam combiner associated with each of said pairs of said first optical fiber and said second optical fiber;
- (f) a second end of each of said second optical fibers positioned to deliver a second portion of said beam from each said beam splitter into each said beam combiner;
- (g) wherein each said beam combiner associated with each of said pairs of said first optical fiber and said second optical fiber is positioned such that a beam from each said beam combiner can be directed into one of a plurality of ignitor lasers;
- and
- (h) a lens to direct output from each said one of a plurality of ignitor lasers into a combustible fuel.
6 more elements
An ignition method comprising:
- (a) splitting an excitation light beam from an excitation light source into at least two portions;
- (b) directing a first portion of said excitation light beam into a beam combiner;
- (c) delaying and directing a second portion of said excitation light beam into said beam combiner;
- (d) combining said first portion of said excitation light beam with said second portion of said excitation light beam to form a combined light beam having pulses from both said first portion and said second portion of said first light beam;
- (e) directing said combined light beam into an ignitor laser;
- and
- (f) directing output of said ignitor laser into a foal point in a combustible fuel.
4 more elements
An ignition apparatus comprising:
- (a) an excitation light source;
- (b) a beam splitter positioned to receive output from said excitation light source;
- (c) a first optical fiber having a first end positioned to receive a first portion of a beam from said beam splitter;
- (d) a second optical fiber having a second end positioned to recive a second portion of said beam from said beam splitter, wherein said second optical fiber is longer than said first optical fiber;
- (e) a second end of said first optical fiber positioned to deliver said first portion of said beam into an optical couplet;
- (f) a second end of said second optical fiber positioned to deliver said second portion of said beam. into said optical coupler;
- (g) a first end of a third optical fiber connected so as to receive output from said optical coupler;
- (h) a second end of said third optical fiber positioned to deliver said beam into a multiplexing device;
- (i) a plurality of other optical fibers each having a first end positioned to receive outputs from said multiplexing device and a second end positioned to deliver said outputs from said multiplexing device into one of a plurality of ignitor lasers, each of which is positioned to direct output into a combustible fuel.
6 more elements
An ignition method comprising:
- (a) multiplexing an excitation light beam from an excitation light source into a plurality of sequenced beams;
- (b) Splitting each of said plurality of sequenced beams into a first portion and a second portion;
- (c) injecting each said first portion of each of said plurality of sequenced beams into a first optical fiber of one of a plurality of pairs of optical fibers, each said pair of optical fibers being positioned to receive said first portion and said second portion from each of said plurality of sequenced beams;
- (d) injecting each said second portion of each of said plurality of sequenced beams into a second optical fiber of one of said plurality of pairs of optical fibers;
- (e) delaying each said second portion of each of said plurality of sequenced beams;
- (f) combining each said first portion of each of said plurality of sequenced beams with each said second portion of each of said plurality of sequenced beams to form a plurality of combined light beams having pulses from both said first portion and said second portion of each of said sequenced beams;
- (g) directing each of said plurality of combined light beams into one of a plurality of ignitor lasers;
- and
- (h) directing output of each of said plurality of ignitor lasers into a focal point in a combustible fuel.
6 more elements
An ignition method comprising:
- (a) splitting an excitation light beam from an excitation light source into a first portion and a second portion;
- (b) directing said first portion into E first optical fiber for delivery of said first portion of said excitation light beam into a beam combiner;
- (c) directing said second portion into a second optical fiber for delivery of said second portion of said excitation light beam into said beam combiner;
- (d) delaying said delivery of said second portion of said excitation light beam into said beam combiner;
- (e) directing output of said beam combiner having pulses from both said first portion and said second portion of excitation light into a multiplexing device;
- (f) multiplexing said output of said beam combiner to produce a plurality of sequenced beams;
- (g) directing each of said plurality of sequenced beams into one of a plurality of ignitor lasers;
- and
- (h) directing output of each of said plurality of ignitor lasers into a focal point in a combustible fuel.
6 more elements
Dependencies are inferred from the claim text.