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US4697272A
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Corrugated reflector apparatus and method for free electron lasers
Assignee: The AT&T MVPD Group LLC
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Filing: 1986-05-09
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Granted: 1987-09-29
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Expires: 2006-05-09
Abstract
Abstract A blazed corrugated reflector having internal corrugations or vanes, blazed at specified design angles, coherently reflects power at specified wavelengths. The corrugations meet the criteria of effecting retroreflection according to the Bragg conditions for gratings, eliminating higher order modes of reflection, and maximizing retroreflection and minimizing forward scattering according to the blaze condition. Two such reflectors can be configured into a laser resonator by placing them at opposing ends of a matching waveguide. The reflector does not obstruct the passage of an axial electron beam, thereby making it suitable to implement the resonator portion of a free electron laser.
Inventors
- 👤 Robin J. Harvey
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 13:43
CPC Classifications
H; H01; H01S; H01S3/00; H01S3/09; H01S3/0903; H01S3/05; H01S3/06; H01S3/063; H01S3/0632; H01S3/0635
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
49 words
A corrugated reflector apparatus for coherent reflection of the power in a wave, comprising; a hollow cylindrical member having a longitudinal axis, and a plurality of blazed vane means, coaxially disposed internally within said member along said axis, for coherently reflecting power of said wave at a specified wavelength.
Claim 2
Dependent Claim
49 words
A corrugated reflector apparatus for coherent reflection of the power in a wave, comprising; a hollow cylindrical member having a longitudinal axis, and a plurality of blazed vane means, coaxially disposed internally within said member along said axis, for coherently reflecting power of said wave at a specified wavelength.
Claim 3
Dependent Claim
65 words
An apparatus as defined in claim 1, wherein said blazed vane means comprises: a plurality of triangularly-shaped corrugations of a configuration whereby retroreflection of said wave occurs according to the Bragg condition for gratings, higher order modes of reflection of said waves are eliminated, and said retroreflection is maximized with said forward scattering of said wave being minimized according to the blaze condition for gratings.
Claim 4
Dependent Claim
25 words
An apparatus as defined in claim 2, wherein: said corrugations are spaced at the longitudinal half-wavelengths of the mode of said wave to be reflected.
Claim 5
Dependent Claim
29 words
An apparatus as defined in claim 2, wherein: said corrugations are shaped such that the incident partial wavefront of said wave is parallel to the surface of said corrugations.
Claim 6
Dependent Claim
39 words
An apparatus as defined in claim 2 wherein said triangular corrugations of said reflector are spaced apart in the transverse direction such that the distance between opposing bases of said corrugations equals the diameter of said hollow elongated member.
Claim 7
Dependent Claim
85 words
A corrugated reflector apparatus for coherent reflection of a certain wavelength of a wave, comprising: a hollow elongated member; and a plurality of triangularly-shaped corrugations disposed coaxially and internally within said member such that the following two relationships are satisfied: ##EQU7## d is the spacing between peaks of adjacent said corrugation, λ is said wavelengh, θ is the incident wave angle of said wave, k is the wave number of said wave, and k c is the cut-off number for said wave in a waveguide.
Claim 8
Dependent Claim
85 words
A corrugated reflector apparatus for coherent reflection of a certain wavelength of a wave, comprising: a hollow elongated member; and a plurality of triangularly-shaped corrugations disposed coaxially and internally within said member such that the following two relationships are satisfied: ##EQU7## d is the spacing between peaks of adjacent said corrugation, λ is said wavelengh, θ is the incident wave angle of said wave, k is the wave number of said wave, and k c is the cut-off number for said wave in a waveguide.
Claim 9
Dependent Claim
58 words
A blazed-distributed-Bragg reflector apparatus for coherent reflection of a wave at at least one wavelength, comprising: a plurality of vane means for effecting retroreflection of said wave according to the Bragg condition for gratings, for effecting cut-off of higher order modes of reflection, and for maximizing retroreflection and minimizing forward scattering according to the blaze condition for gratings.
Claim 10
Dependent Claim
58 words
A blazed-distributed-Bragg reflector apparatus for coherent reflection of a wave at at least one wavelength, comprising: a plurality of vane means for effecting retroreflection of said wave according to the Bragg condition for gratings, for effecting cut-off of higher order modes of reflection, and for maximizing retroreflection and minimizing forward scattering according to the blaze condition for gratings.
Claim 11
Independent Claim
61 words
A method for effecting coherent reflection of a wave at at least one wavelength, comprising: directing said wave against a plurality of vane means for effecting retroreflection of said wave according to the Bragg condition for gratings, for effecting cut-off of higher order modes of reflection, and for maximizing retroreflection and minimizing forward scattering according to the blaze condition for gratings.
Claim 12
Independent Claim
61 words
A method for effecting coherent reflection of a wave at at least one wavelength, comprising: directing said wave against a plurality of vane means for effecting retroreflection of said wave according to the Bragg condition for gratings, for effecting cut-off of higher order modes of reflection, and for maximizing retroreflection and minimizing forward scattering according to the blaze condition for gratings.
Claim 13
Independent Claim
102 words
A method for coherently reflecting waves at a specified wavelength, comprising: directing said waves into a hollow elongated member having a plurality of triangularly-shaped corrugations disposed coaxially and internally with said member such that the following three relationships are satisfied: ##EQU8## r is half the distance between the opposing bases of the corrugations, n is an integer, d is the spacing between the peaks of adjacent said corrugation, λ is said wavelength, θ is the incident wave angle of said wave, k is the wave number of said wave, and k c is the cut-off number for said wave in a waveguide.
Claim 14
Independent Claim
102 words
A method for coherently reflecting waves at a specified wavelength, comprising: directing said waves into a hollow elongated member having a plurality of triangularly-shaped corrugations disposed coaxially and internally with said member such that the following three relationships are satisfied: ##EQU8## r is half the distance between the opposing bases of the corrugations, n is an integer, d is the spacing between the peaks of adjacent said corrugation, λ is said wavelength, θ is the incident wave angle of said wave, k is the wave number of said wave, and k c is the cut-off number for said wave in a waveguide.
Claim 15
Dependent Claim
41 words
A laser resonating cavity apparatus comprising: elongated waveguide means; and a pair of corrugated reflectors disposed at opposing ends of said waveguide means, said reflectors each comprising a plurality of blazed vane means for coherently reflecting power at a specified wavelength.
Claim 16
Dependent Claim
41 words
A laser resonating cavity apparatus comprising: elongated waveguide means; and a pair of corrugated reflectors disposed at opposing ends of said waveguide means, said reflectors each comprising a plurality of blazed vane means for coherently reflecting power at a specified wavelength.
Claim 17
Dependent Claim
29 words
An apparatus as defined in claim 10 wherein: said reflectors each comprise a hollow tube member; and said blazed vane means are coaxially disposed internally within said tube member.
Claim 18
Dependent Claim
65 words
An apparatus as defined in claim 10 wherein said blazed vane means comprises: a plurality of triangularly-shaped corrugations of a configuration whereby retroreflection of said wave occurs according to the Bragg condition for gratings, higher order modes of reflection of said waves are eliminated, and said retroreflection is maximized with said forward scattering of said wave being minimized according to the blaze conditions for gratings.
Claim 19
Dependent Claim
64 words
An apparatus as defined in claim 12 wherein: the number M of said corrugations satisfies the relation: ##EQU9## N is the number of half-wavelengths between said corrugations measured at an angle θ; is the angle of incidence of said wave upon said waveguide wall, and m is the number of said corrugations encompassed by the wave in crossing the reflector at an angle θ.
Claim 20
Dependent Claim
104 words
An apparatus as defined in claim 10 wherein: said reflectors each comprise a hollow and elongated tube member; and said blazed vane means comprises a plurality of triangularly-shaped corrugations disposed coaxially and internally within said member such that the following three relationships are satisfied: ##EQU10## 2r is the distance between the walls of the waveguide, n is an integer, d is the spacing between the peaks of adjacent said corrugations, λ is said wavelength, θ is the incident wave angle of said wave, k is the wave number of said wave, and k c is the cut-off number for said wave in a waveguide.
Claim 21
Dependent Claim
28 words
An apparatus as defined in claim 10 wherein said waveguide means has a length equal to an integer number of half wavelengths of said wavelength to be reflected.
Claim 22
Dependent Claim
68 words
A free electron laser apparatus having means for producing an electron beam and laser cavity resonator means for modulating said electron beam to produce intense coherent radiation wherein said laser cavity means comprises: elongated waveguide means; and a pair of corrugated reflectors disposed at opposing ends of said waveguide means, said reflectors each comprising a plurality of blazed vane means for coherently reflecting power at a specified wavelength.
Claim 23
Dependent Claim
68 words
A free electron laser apparatus having means for producing an electron beam and laser cavity resonator means for modulating said electron beam to produce intense coherent radiation wherein said laser cavity means comprises: elongated waveguide means; and a pair of corrugated reflectors disposed at opposing ends of said waveguide means, said reflectors each comprising a plurality of blazed vane means for coherently reflecting power at a specified wavelength.
References Cited (Backward Citations)
US4367551A
Cited
US4438513A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-09-28 | 1991-03-30 | 1991-09-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-09-28 | 1995-03-30 | 1995-09-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-09-28 | 1999-03-30 | 1999-09-29 | $7700.00 | Window Closed / Lapsed |