US5373526A — Apparatus and method for optical energy amplifica…

Claim 1

Independent Claim 252 words

An optical energy transfer system, comprising: means for producing a first coherent optical beam having a first predetermined wavelength and frequency, means for producing a coherent pump optical beam having a predetermined wavelength and frequency which are different from the wavelength and frequency of said first beam, means for diverting a portion of said first beam to establish a probe beam having the predetermined frequency of said first beam, with the remaining portion of said first beam undiverted, means for modulating the frequency of said probe beam, a first host medium having a rare earth dopant, said rare earth dopant having an energy transition from said pump beam's wavelength to the wavelength of said first beam, first coupling means for coupling said pump beam and the undiverted portion of said first beam into said first host medium, said pump beam amplifying said first beam within said host medium by an energy transfer from said pump beam to said first beam via the energy transition of said rare earth dopant, a second host medium having a rare earth dopant, said second host medium and its rare earth dopant providing a resonant energy transfer medium between, and being located in the paths of, said amplified first beam and said modulated probe beam, and second coupling means for coupling said amplified first beam and said modulated probe beam into said second host medium for amplification of said modulated probe beam by a resonant energy transfer from said amplified first beam to said modulated probe beam.

Claim 2

Dependent Claim 252 words

An optical energy transfer system, comprising: means for producing a first coherent optical beam having a first predetermined wavelength and frequency, means for producing a coherent pump optical beam having a predetermined wavelength and frequency which are different from the wavelength and frequency of said first beam, means for diverting a portion of said first beam to establish a probe beam having the predetermined frequency of said first beam, with the remaining portion of said first beam undiverted, means for modulating the frequency of said probe beam, a first host medium having a rare earth dopant, said rare earth dopant having an energy transition from said pump beam's wavelength to the wavelength of said first beam, first coupling means for coupling said pump beam and the undiverted portion of said first beam into said first host medium, said pump beam amplifying said first beam within said host medium by an energy transfer from said pump beam to said first beam via the energy transition of said rare earth dopant, a second host medium having a rare earth dopant, said second host medium and its rare earth dopant providing a resonant energy transfer medium between, and being located in the paths of, said amplified first beam and said modulated probe beam, and second coupling means for coupling said amplified first beam and said modulated probe beam into said second host medium for amplification of said modulated probe beam by a resonant energy transfer from said amplified first beam to said modulated probe beam.

Claim 3

Dependent Claim 35 words

The optical energy transfer system of claim 1, wherein said modulated probe beam is substantially diffraction limited and said amplified first beam is substantially non-diffraction limited when they are coupled into said second host medium.

Claim 4

Dependent Claim 34 words

The optical energy transfer system of claim 1, wherein said pump beam producing means produces said pump beam at a substantially higher power level than said first beam producing means produces said first beam.

Claim 5

Dependent Claim 33 words

The optical energy transfer system of claim 3, wherein the wavelengths of said first and pump beams are respectively about 1.55 and 0.98 microns, and said first host medium is doped with erbium.

Claim 6

Dependent Claim 40 words

The optical energy transfer system of claim 1, said modulating means comprising means for frequency modulating said probe beam to establish a resonant energy transfer interference pattern between said modulated probe and amplified first beams within said second host medium.

Claim 7

Dependent Claim 42 words

The optical energy transfer system of claim 5, said second host medium having a predetermined optical energy transfer response bandwidth, wherein the bandwidth of said frequency modulating means is less than the optical energy transfer response bandwidth of said second host medium.

Claim 8

Dependent Claim 21 words

The optical energy transfer system of claim 5, wherein said modulating means has a modulating frequency substantially greater than 100 KHz.

Claim 9

Dependent Claim 15 words

The optical energy transfer system of claim 5, said modulating means comprising an acousto-optic modulator.

Claim 10

Dependent Claim 45 words

The optical energy transfer system of claim 1, said first host medium comprising a plurality of optical fibers disposed to receive an input from said first coupling means at one end and to provide an output to said second coupling means at their opposite ends.

Claim 11

Dependent Claim 67 words

The optical energy transfer system of claim 9, wherein the input ends of said optical fibers are arranged in an m×m array, and said first coupling means comprises a pair of 1×m mutually orthogonal binary phase gratings oriented to divide said first and pump beams into an m×m array aligned with the input ends of said optical fibers, and means for combining said first and pump beams.

Claim 12

Dependent Claim 43 words

The optical energy transfer system of claim 10, wherein separate pairs of mutually orthogonal binary phase gratings are provided to divide said first and pump beams into respective m×m arrays, and said beam combining means combines said m×m first and pump beam arrays.

Claim 13

Dependent Claim 32 words

The optical energy transfer system of claim 9, said fibers having cladded cores with predetermined core areas, wherein the areas of said cores are expanded at the input ends of said fibers.

Claim 14

Dependent Claim 49 words

The optical energy transfer system of claim 9, said fibers comprising cores surrounded by cladding layers, wherein the thickness of said cladding layers is reduced at the output ends of said fibers, and further comprising means holding the output ends of said fibers in close proximity to each other.

Claim 15

Dependent Claim 30 words

The optical energy transfer system of claim 9, wherein said fibers are joined to each other at their input ends, and separated in a spaced array at their output ends.

Claim 16

Dependent Claim 26 words

The optical energy transfer system of claim 14, said first coupling means focusing said first and pump beams directly onto the input ends of said fibers.

Claim 17

Dependent Claim 93 words

The optical energy transfer system of claim 14, wherein the areas of said fibers are reduced at their input ends, and said first coupling means includes a coupling optical fiber that is single mode with respect to said first beam, said coupling fiber having an input end that is enlarged with respect to the input ends of said host medium fibers and an output end positioned to illuminate the input ends of said host medium fibers, and means for focusing said first and pump beams onto the input end of said coupling fiber.

Claim 18

Dependent Claim 33 words

The optical energy transfer system of claim 16, wherein the output end of said coupling fiber is enlarged with respect to the portion of the coupling fiber between its input and output ends.

Claim 19

Dependent Claim 87 words

The optical energy transfer system of claim 14, wherein the areas of said fibers are reduced at their input ends and said first coupling means includes a plurality of single-mode optical coupling fibers having output ends positioned to illuminate said host medium fibers and input ends, and means for focusing said first beam onto the input end of at least one of said coupling fibers and said pump beam onto the input ends of a greater number of coupling fibers than those that receive said first beam.

Claim 20

Dependent Claim 16 words

The optical energy transfer system of claim 1, said first host medium comprising an optical waveguide.

Claim 21

Dependent Claim 21 words

The optical energy transfer system of claim 1, said means for generating said first and pump beams comprising respective optical lasers.

Claim 22

Dependent Claim 179 words

An optical energy transfer system, comprising: first and second sources of coherent first and coherent pump optical beams at different respective wavelengths and frequencies, means for diverting a portion of said first beam into a probe beam having the same frequency as first beam, means for modulating the frequency of said probe beam, means for transferring energy from said pump beam to said first beam after diversion of said probe beam, thereby amplifying said first beam, a rare earth doped resonant transfer host medium that provides a resonant energy transfer medium between, and is located in the paths of, said amplified first beam and said modulated probe beam, and means for coupling said frequency modulated probe beam and amplified first beam within said resonant transfer host medium so that they beat against each other and generate interference gratings as a result of frequency differences between the frequency modulated probe and amplified first beams, said gratings producing a coherent scattering of the amplified first beam that effects a resonant energy transfer from said amplified first beam to said probe beam.

Claim 23

Dependent Claim 179 words

An optical energy transfer system, comprising: first and second sources of coherent first and coherent pump optical beams at different respective wavelengths and frequencies, means for diverting a portion of said first beam into a probe beam having the same frequency as first beam, means for modulating the frequency of said probe beam, means for transferring energy from said pump beam to said first beam after diversion of said probe beam, thereby amplifying said first beam, a rare earth doped resonant transfer host medium that provides a resonant energy transfer medium between, and is located in the paths of, said amplified first beam and said modulated probe beam, and means for coupling said frequency modulated probe beam and amplified first beam within said resonant transfer host medium so that they beat against each other and generate interference gratings as a result of frequency differences between the frequency modulated probe and amplified first beams, said gratings producing a coherent scattering of the amplified first beam that effects a resonant energy transfer from said amplified first beam to said probe beam.

Claim 24

Dependent Claim 59 words

The optical energy transfer system of claim 21, wherein said first beam source generates said first beam and probe beam as substantially diffraction limited beams, said energy transfer means causes said amplified first beam to be substantially non-diffraction-limited, and said resonant transfer host medium substantially preserves the diffraction limited quality of said probe beam during said energy transfer thereto.

Claim 25

Dependent Claim 30 words

The optical energy transfer system of claim 21, wherein said first and second optical beam sources generate said first and pump beams at about 1.55 microns and 0.98 microns, respectively.

Claim 26

Dependent Claim 54 words

The optical energy transfer system of claim 21, said energy transfer means comprising a first host medium having a rare earth dopant with an energy transition from the wavelength of said pump beam to the wavelength of said first beam, and means for coupling said first and pump beams into said first host medium.

Claim 27

Dependent Claim 57 words

An optical fiber array, comprising: a plurality of elongate optical fibers having respective optical cores surrounded by cladding layers, the thickness of the cladding layer for each of the fibers being reduced in the vicinity of one end of the fibers, and means holding said reduced thickness ends of the fibers in close proximity to each other.

Claim 28

Dependent Claim 57 words

An optical fiber array, comprising: a plurality of elongate optical fibers having respective optical cores surrounded by cladding layers, the thickness of the cladding layer for each of the fibers being reduced in the vicinity of one end of the fibers, and means holding said reduced thickness ends of the fibers in close proximity to each other.

Claim 29

Dependent Claim 27 words

The optical fiber array of claim 25, wherein the opposite ends of said fibers from said reduced thickness ends are joined together in a common optical fiber.

Claim 30

Dependent Claim 109 words

A diffraction limited method of transferring energy from a coherent optical pump beam at one wavelength to a first optical beam at another wavelength, comprising: generating said first beam as a substantially diffraction limited coherent beam, diverting a portion of said first beam as a substantially diffraction limited coherent probe beam, transferring energy from said pump beam to said first beam after diversion of said probe beam to yield a substantially non-diffraction limited amplified first beam, and transferring energy from said amplified first beam to said probe beam in a substantially diffraction-limited energy transfer process to yield a substantially diffraction limited amplified probe beam at said first beam wavelength.

Claim 31

Dependent Claim 109 words

A diffraction limited method of transferring energy from a coherent optical pump beam at one wavelength to a first optical beam at another wavelength, comprising: generating said first beam as a substantially diffraction limited coherent beam, diverting a portion of said first beam as a substantially diffraction limited coherent probe beam, transferring energy from said pump beam to said first beam after diversion of said probe beam to yield a substantially non-diffraction limited amplified first beam, and transferring energy from said amplified first beam to said probe beam in a substantially diffraction-limited energy transfer process to yield a substantially diffraction limited amplified probe beam at said first beam wavelength.

Claim 32

Dependent Claim 48 words

The method of claim 27, wherein energy is transferred from said pump beam to said first beam by transmitting said beams through a host medium having a rare earth dopant with an energy transition from the wavelength of said pump beam to the wavelength of said first beam.

Claim 33

Dependent Claim 67 words

The method of claim 27, wherein energy is transferred from said amplified first beam to said probe beam by frequency modulating said probe beam, and beating said frequency modulated probe beam against said amplified first beam in a host medium having a rare earth dopant to generate optical gratings in said medium that scatter said amplified first beam to effect a resonant energy transfer between said beams.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1997-12-12	1998-06-13	1998-12-13	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	2001-12-12	2002-06-13	2002-12-13	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	2005-12-12	2006-06-13	2006-12-13	$7700.00	Window Closed / Lapsed

Apparatus and method for optical energy amplification using two-beam coupling

Abstract

Inventors

Bibliographic Details

Claims Analysis

References Cited (Backward Citations)

USPTO Annuity & Maintenance Windows

Assigned Categories & Tags

Assign Category Tag