Spectrally beam combined laser system and method at eye-safer wavelengths
First Claim
Patent Images
1. A method comprising:
- providing a plurality of Raman optical fibers including a first optical fiber and a second optical fiber;
providing a plurality of intermediate-wavelength grating pairs, wherein each intermediate-wavelength grating pair of the plurality of intermediate-wavelength grating pairs is configured to resonate at one or more of a plurality of different intermediate Raman-shifted wavelengths;
providing at least a first common grating;
optically coupling the first common grating to both the first optical fiber and the second optical fiber;
generating a plurality of different output wavelengths of laser light, wherein the plurality of different output wavelengths includes a first output wavelength and a second output wavelength;
successively Raman shifting a base-wavelength Raman pump light in each one of the plurality of optical fibers to each successive one of the plurality of different intermediate Raman-shifted wavelengths;
Raman amplifying, in each of the plurality of optical fibers, the plurality of different output wavelengths, each of which is longer than 1300 nm; and
spectral-beam combining the plurality of Raman amplified wavelengths into a single output beam.
1 Assignment
0 Petitions
Accused Products
Abstract
Fiber-laser light is Raman shifted to eye-safer wavelengths prior to spectral beam combination, enabling a high-power, eye-safer wavelength directed-energy (DE) system. The output of Ytterbium fiber lasers is not used directly for spectral beam combining. Rather, the power from the Yb fiber lasers is Raman-shifted to longer wavelengths, and these wavelengths are then spectrally beam combined. Raman shifting is most readily accomplished with a “cascaded Raman converter,” in which a series of nested fiber cavities is formed using fiber Bragg gratings.
194 Citations
22 Claims
-
1. A method comprising:
-
providing a plurality of Raman optical fibers including a first optical fiber and a second optical fiber; providing a plurality of intermediate-wavelength grating pairs, wherein each intermediate-wavelength grating pair of the plurality of intermediate-wavelength grating pairs is configured to resonate at one or more of a plurality of different intermediate Raman-shifted wavelengths; providing at least a first common grating; optically coupling the first common grating to both the first optical fiber and the second optical fiber; generating a plurality of different output wavelengths of laser light, wherein the plurality of different output wavelengths includes a first output wavelength and a second output wavelength; successively Raman shifting a base-wavelength Raman pump light in each one of the plurality of optical fibers to each successive one of the plurality of different intermediate Raman-shifted wavelengths; Raman amplifying, in each of the plurality of optical fibers, the plurality of different output wavelengths, each of which is longer than 1300 nm; and spectral-beam combining the plurality of Raman amplified wavelengths into a single output beam. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
-
-
14. An apparatus comprising:
-
a plurality of optical-fiber Raman amplifiers including a first optical-fiber Raman amplifier and a second optical-fiber Raman amplifier; a plurality of intermediate-wavelength grating pairs, wherein each intermediate-wavelength grating pair of the plurality of intermediate-wavelength grating pairs is configured to resonate at one or more of a plurality of different intermediate Raman-shifted wavelengths; a first common grating, wherein the first common grating is optically coupled to both the first optical-fiber Raman amplifier and the second optical-fiber Raman amplifier; an output-wavelength generator that generates a plurality of different output wavelengths of laser light that includes a first output wavelength and a second output wavelength, wherein each one of the plurality of optical-fiber Raman amplifiers is further configured to successively Raman shift a base-wavelength Raman pump light to each successive one of the plurality of different intermediate Raman-shifted wavelengths, and to Raman amplify the plurality of different output wavelengths, each of which is longer than 1300 nm; and a spectral-beam combiner using at least one high-efficiency grating that is operably coupled to receive the plurality of different output wavelengths from the plurality of optical-fiber Raman amplifiers and configured to combine the plurality of different output wavelengths into a single output beam. - View Dependent Claims (15, 16, 17, 18, 19, 20, 21, 22)
-
Specification