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US4654532A Expired / Lapsed US ⏱️ 0.0 years remaining

Apparatus for improving the numerical aperture at the input of a fiber optics device

Assignee: ORD Inc NAHANT MASSACHUSETTS A CORP OF MASSACHUSETTS
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Filing: 1985-09-09
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Granted: 1987-03-31
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Expires: 2005-09-09
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Abstract

Abstract An optical wave guide particularly useful in assay apparatus employing total internal reflection of excitation radiation at the interface between the wave guide and a surrounding liquid phase of lower index of refraction. The wave guide in the form of a solid, light-transmissive, elongated rod or fiber made typically of glass, crystal or plastic and having preferably a circular cross-section, is tapered gradually from an entrance face of relatively large diameter to a substantially smaller diameter at some position longitudinally displaced from the entrance face. In one form, the wave guide is formed with a tapering conical input portion coupled to a second portion having a cylindrical configuration and a diameter matched to the smaller diameter of the tapered portion.

Inventors

  • 👤 Tomas B. Hirschfeld

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-25 12:25
CPC Classifications
G; G01; G01N; G01N21/00; G01N21/62; G01N21/63; G01N21/64; G01N21/645; G01N21/648; G01N21/75; G01N21/77; G01N21/7703; G02; G02B; G02B6/00; G02B6/24; G02B6/42; G02B6/4201; G02B6/4202; G02B6/4203; G01N2021/6484; G01N21/6428

Claims Analysis

Total Claims: 18
Claim 1
Independent Claim 98 words
Optical apparatus comprising, in combination, a radiation source, and an optical fiber transmissive to said radiation and comprising a first section of unclad fiber of substantially uniform cross-section diameter providing a region with a substantially constant numerical aperture, said first section being coupled to a second section of said fiber having an entrance face into which said radiation can be introduced, at least part of the periphery of said second section having cladding thereon, said second section being tapered smoothly so as to reduce the diameter thereof from said entrance face to the diameter of said first section.
Claim 2
Dependent Claim 98 words
Optical apparatus comprising, in combination, a radiation source, and an optical fiber transmissive to said radiation and comprising a first section of unclad fiber of substantially uniform cross-section diameter providing a region with a substantially constant numerical aperture, said first section being coupled to a second section of said fiber having an entrance face into which said radiation can be introduced, at least part of the periphery of said second section having cladding thereon, said second section being tapered smoothly so as to reduce the diameter thereof from said entrance face to the diameter of said first section.
Claim 3
Dependent Claim 16 words
Optical apparatus as defined in claim 1 wherein said fiber is tapered less than about 5°.
Claim 4
Dependent Claim 16 words
Optical apparatus as defined in claim 1 wherein said radiation source is a solid-state radiation emitter.
Claim 5
Dependent Claim 14 words
Optical apparatus as defined in claim 1 wherein said radiation source is a laser.
Claim 6
Dependent Claim 24 words
Optical apparatus as defined in claim 1 including detection means optically coupled to said entrance face to detect radiation travelling back down said fiber.
Claim 7
Dependent Claim 27 words
Optical apparatus as defined in claim 1 wherein the numerical aperture at said region is greater than about 1.0 when said region is surrounded by a fluid.
Claim 8
Dependent Claim 26 words
Optical apparatus as defined in claim 1 including a radiation absorbing collar disposed in contact about said fiber intermediate said entrance face and said first section.
Claim 9
Dependent Claim 195 words
In optical apparatus for performing, on a fluid sample, immunoassays with a reagent incorporating a fluorescent tag capable of emitting fluorescent radiation when excited by exciting radiation, said apparatus including an optical fiber transmissive to both said exciting radiation and said fluorescent radiation and having an entrance face into which said exciting radiation can be propagated so as to create within a zone bounded by at least a portion of the surface of said fiber in contact with said sample, an evanescent wave capable of exciting fluorescent radiation from tags that may be disposed in said zone, the improvement wherein said fiber comprises a first section of unclad fiber of substantially uniform cross-section diameter, said zone being located in said first section so as to probide said zone with a substantially constant numerical aperture, said first section being coupled to one end of a second section of said fiber having said entrance face at the opposite end thereof, at least part of the periphary of said second section having cladding thereon, said second section being tapered smoothly so as to reduce the diameter thereof from said entrance face to the diameter of said first section.
Claim 10
Dependent Claim 195 words
In optical apparatus for performing, on a fluid sample, immunoassays with a reagent incorporating a fluorescent tag capable of emitting fluorescent radiation when excited by exciting radiation, said apparatus including an optical fiber transmissive to both said exciting radiation and said fluorescent radiation and having an entrance face into which said exciting radiation can be propagated so as to create within a zone bounded by at least a portion of the surface of said fiber in contact with said sample, an evanescent wave capable of exciting fluorescent radiation from tags that may be disposed in said zone, the improvement wherein said fiber comprises a first section of unclad fiber of substantially uniform cross-section diameter, said zone being located in said first section so as to probide said zone with a substantially constant numerical aperture, said first section being coupled to one end of a second section of said fiber having said entrance face at the opposite end thereof, at least part of the periphary of said second section having cladding thereon, said second section being tapered smoothly so as to reduce the diameter thereof from said entrance face to the diameter of said first section.
Claim 11
Dependent Claim 14 words
Optical apparatus as defined in claim 8 wherein said reagent is an antigen-antibody complex.
Claim 12
Dependent Claim 29 words
Optical apparatus as defined in claim 8 including means for delimiting a volume including said zone and bounded, at least in part, by said portion of said fiber surface.
Claim 13
Dependent Claim 14 words
Optical apparatus as defined in claim 10 wherein said volume is of capillary dimensions.
Claim 14
Dependent Claim 28 words
Optical apparatus as defined in claim 10 wherein said means for delimiting comprises elongated enclosure means surrounding and spaced from at least said portion of said fiber surface.
Claim 15
Dependent Claim 88 words
Optical apparatus as defined in claim 8 wherein the numerical aperture of said fiber at said zone is defined as (n o 2 -n 1 2 )1/2, n o and n l being respectively the indices of refraction of said fiber and said sample, and wherein the numerical aperture at said entrance face is lesser than said numerical aperture at said zone, the angle of said taper being chosen to provide said numerical aperture at said zone substantially without radiation loss though the tapered surface of said fiber.
Claim 16
Dependent Claim 55 words
Optical apparatus as defined in claim 8 including a radiation absorbing collar disposed in contact about said fiber adjacent the juncture of said first and second sections, the material of said collar in contact with said fiber being selected to have an index of refraction substantially matched to the index of refraction of said sample.
Claim 17
Dependent Claim 24 words
Optical apparatus as defined in claim 8 including detection means optically coupled to said entrance face to detect radiation travelling back down said fiber.
Claim 18
Dependent Claim 19 words
Optical apparatus as defined in claim 8 wherein the numerical aperture at said zone is greater than about unity.

References Cited (Backward Citations)

US3779628A Cited
US4133639A Cited
US4167746A Cited
US4050895A Cited
US4321057A Cited
US4399099A Cited
US4521070A Cited
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USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1990-03-30 1990-09-29 1991-03-31 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1994-03-30 1994-09-29 1995-03-31 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1998-03-30 1998-09-29 1999-03-31 $7700.00 Window Closed / Lapsed

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