US4345815A
Expired / Lapsed
US
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Perfect geodesic lens for waveguides and optical processor of unidimensional signals employing said lens
Assignee: Consiglio Nazionale delle Richerche
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Filing: 1979-08-03
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Granted: 1982-08-24
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Expires: 1999-08-03
Abstract
Abstract A geodesic lens for waveguides formed by four concentric zones, of which the two exterior ones, having an external radius a and b, are portions of a plane surface, the central zone, having a radius d, represents the actual lens, and the remaining zone, having an external radius c, is a connecting portion without discontinuities with the contiguous portions having an external radius respectively equal to d and b, said parameters a, b, d, having been selected according to the optical characteristics of the lens to be obtained, taking into account the formulae: focal length f=ab/(a+b), aperture=2d, linear magnification X=b/a (or X=a/b according to the position of the image with respect to the source).
Inventors
- 👤 Giancarlo Righini
- 👤 Stefano Sottini
- 👤 Vera Russo
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 08:09
CPC Classifications
G; G02; G02B; G02B6/00; G02B6/10; G02B6/12; G02B6/122; G02B6/124; G02B6/1245; H; H01; H01Q; H01Q15/00; H01Q15/02; H01Q15/04
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
215 words
Geodesic lens for optical waveguides characterized in that it is formed by four concentric zones (4,3,2,1), of which the two external ones (4,3), having an external radius a and b, are portions of a plane surface, the central zone (1), having a radius d, represents the actual lens, and the remaining zone (2), having an external radius c, is a connecting portion without discontinuities with the contiguous portions (1,3), having the external radius respectively equal to d and b, said connecting zone (2) being described by its meridian curve l(ρ), which can be arbitrarily chosen, provided that l'(ρ) be continuous for d≦ρ≦c and match with continuity the l'(ρ) of the surface under the parallel of radius d for ρ=d and the l'(ρ) of the plane for ρ=c, said central zone (1) being described by its meridian curve l(ρ), obtained by integrating the following formula: ##EQU9## where F'(ψ) is the derivative of the function F(ψ) expressing the longitude travelled by a ray in the surface under the parallel d, said parameters a, b, d having been selected according to the optical characteristics of the lens to be obtained, taking into account the formulae: focal length f=ab/(a+b), aperture=2d, linear magnification X=b/a (or X=a/b, according to the position of the image (9) with respect to the source (10)).
Claim 2
Dependent Claim
215 words
Geodesic lens for optical waveguides characterized in that it is formed by four concentric zones (4,3,2,1), of which the two external ones (4,3), having an external radius a and b, are portions of a plane surface, the central zone (1), having a radius d, represents the actual lens, and the remaining zone (2), having an external radius c, is a connecting portion without discontinuities with the contiguous portions (1,3), having the external radius respectively equal to d and b, said connecting zone (2) being described by its meridian curve l(ρ), which can be arbitrarily chosen, provided that l'(ρ) be continuous for d≦ρ≦c and match with continuity the l'(ρ) of the surface under the parallel of radius d for ρ=d and the l'(ρ) of the plane for ρ=c, said central zone (1) being described by its meridian curve l(ρ), obtained by integrating the following formula: ##EQU9## where F'(ψ) is the derivative of the function F(ψ) expressing the longitude travelled by a ray in the surface under the parallel d, said parameters a, b, d having been selected according to the optical characteristics of the lens to be obtained, taking into account the formulae: focal length f=ab/(a+b), aperture=2d, linear magnification X=b/a (or X=a/b, according to the position of the image (9) with respect to the source (10)).
Claim 3
Dependent Claim
23 words
Geodesic lens according to claim 1 characterized in that the external radius of the most external zone (4) tends toward the infinite (a→∞).
Claim 4
Dependent Claim
49 words
Geodesic lens according to claim 1 characterized in that the profile l(ρ) of the connecting surface (2) is described by the formula: ##EQU10## wherein h is a parameter which depends from the ratios d/c=sin γ 12 , d/b=sin γ 13 and d/a=sin γ 14 according to the expression: ##EQU11##
Claim 5
Dependent Claim
221 words
Optical processor of unidimensional signals, including: an optical waveguide formed by a thin film of a material, transparent to the laser radiation adopted, supported by a substrate made of a material having a refraction index inferior to that of the thin film; an optical system, manufactured on said substrate, formed by two geodesic lenses according to claim 1 the first of which having parameters a,b,c,d and the second one having parameters a',b',c',d', in such a way that the distance between the centers of the two lenses be equal or greater than the sum of the radius c of the first lens and of the radius a' of the second one; a signal insertion point along a line located perpendicularly to the axis which unites the centers of the two lenses, and situated, between the two lenses, at a distance a' from the center of the second lens; a filter point located on a line parallel to the input line, at a distance a from the center of the first lens, and a signal output point located on a circle having radius equal to the focal length f of the second lens and having their center in a point situated on the line passing through the centers of the two lenses, at a distance a'-f from the center of said second lens.
Claim 6
Dependent Claim
27 words
Optical processor of unidimensional signals according to claim 4 characterized in that at least one of the two lenses pertains to the type with parameters a→∞, b,c,d.
Claim 7
Dependent Claim
166 words
Geodesic lens for waveguides characterized in that it is formed by four concentric zones (4,3,2,1), of which the two exterior ones (4,3), having an external radius a and b, are portions of a plane surface, the central zone (1) having a radius d represents the actual lens, and the remaining zone (2), having an external radius c, is a connecting portion without discontinuities with the contiguous portions (1,3) having an external radius respectively equal to d and b, said parameters a, b, d, having been selected according to the optical characteristics of the lens to be obtained, taking into account the formulae: focal length f=ab/(a+b), aperture=2d, linear magnification X=b/a (or X=a/b, according to the position of the image (9) with respect to the source (10), and the profile z(p) of the connecting surface (3) is described by the formula: ##EQU12## wherein h is a parameter which depends from the ratios d/c=sin γ 12 , d/b=sin γ 13 and d/a=sin γ 14 according to the expression: ##EQU13##
Claim 8
Dependent Claim
166 words
Geodesic lens for waveguides characterized in that it is formed by four concentric zones (4,3,2,1), of which the two exterior ones (4,3), having an external radius a and b, are portions of a plane surface, the central zone (1) having a radius d represents the actual lens, and the remaining zone (2), having an external radius c, is a connecting portion without discontinuities with the contiguous portions (1,3) having an external radius respectively equal to d and b, said parameters a, b, d, having been selected according to the optical characteristics of the lens to be obtained, taking into account the formulae: focal length f=ab/(a+b), aperture=2d, linear magnification X=b/a (or X=a/b, according to the position of the image (9) with respect to the source (10), and the profile z(p) of the connecting surface (3) is described by the formula: ##EQU12## wherein h is a parameter which depends from the ratios d/c=sin γ 12 , d/b=sin γ 13 and d/a=sin γ 14 according to the expression: ##EQU13##
References Cited (Backward Citations)
GB1434457A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1985-08-23 | 1986-02-22 | 1986-08-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-08-23 | 1990-02-22 | 1990-08-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-08-23 | 1994-02-22 | 1994-08-24 | $7700.00 | Window Closed / Lapsed |