Laser ignition
AssigneeThe Regents of the University of California
InventorsJames W. Early, Charles S. Lester
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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. 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. In the embodiment of the invention claimed herein, 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 combined with either the first portion after a delay before injection into the ignitor laser.
Claims43
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 connected to an ignitor laser so as to permit transport of a first portion of a beam from said excitation light source into said ignitor laser;
- (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 a beam from said beam splitter into a beam combiner positioned such that a beam from said ignitor laser can also be directed into said beam combiner;
- and
- (g) a lens to direct a combined beam from said beam combiner into a combustible fuel.
An ignition apparatus comprising:
- (a) an excitation light source;
- (b) an optical switch positioned to receive output from said excitation light source and direct said output from said excitation light source into a plurality of beam splitters;
- (c) a plurality of pairs of a first 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 connected to an ignitor laser so as to permit transport of a first portion of a beam from said excitation light source into each said ignitor laser;
- (f) a second end of each of said second optical fibers positioned to deliver a second portion of a beam from each said beam splitter into a beam combiner positioned such that a beam from each said ignitor laser can also be directed into said beam combiner;
- and
- (g) a lens to direct a combined beam from each said beam combiner into a combustible fuel.
An ignition method comprising:
- (a) splitting a beam from an excitation light source into at least two portions;
- (b) directing a first portion of said excitation light beam through a first optical fiber into an ignitor laser, causing output of an ignitor laser beam;
- (c) directing a second portion of said excitation light beam through a second optical fiber into a beam combiner;
- (d) combining said second portion of said excitation light beam with said ignitor laser beam to form a combined laser beam;
- and
- (e) directing said combined laser beam into a focal point in a combustible fuel.
Dependencies are inferred from the claim text.