US4422733A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Cladded spherical lens having uneven refractive index
Assignee: National Institute of Advanced Industrial Science and Technology
•
Filing: 1981-03-18
•
Granted: 1983-12-27
•
Expires: 2001-03-18
Abstract
Abstract A cladded lens having an uneven refractive index comprises a spherical core having a graded refractive index and producing negative lateral aberration and a cladding producing positive lateral aberration. The aberrations of the core and the cladding are canceled by each other to be considerably corrected. Such a cladded lens is especially effective for optical communication and optical recording-regenerating as in PCM technology.
Inventors
- 👤 Keisuke Kikuchi
- 👤 Takitaro Morikawa
- 👤 Junichi Shimada
- 👤 Kenjiro Sakurai
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 16:35
CPC Classifications
G; G02; G02B; G02B3/00; G02B3/0087
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
131 words
A cladded lens having an uneven refractive index, comprising: (a) a core having a radius (r o ) and a refractive index (n(r)) continuously graded in proportion to the distance (r) from the center thereof according to the formula: n.sup.2 (r)=n.sup.2 (o)[1+G.sub.2 (r/r.sub.o).sup.2 +G.sub.4 (r/r.sub.o).sup.4 ] where n(o) is the refractive index at the center of the core, and G 2 and G 4 the secondary- and fourth-order coefficients representing the distribution of the graded refractive index of the core; and (b) a cladding covering at least a portion of the outer periphery of said core and having a thickness and a refractive index which are determined in accordance with the refractive index at the center of said core, whereby the aberration can be reduced below the diffraction limit of light.
Claim 2
Dependent Claim
131 words
A cladded lens having an uneven refractive index, comprising: (a) a core having a radius (r o ) and a refractive index (n(r)) continuously graded in proportion to the distance (r) from the center thereof according to the formula: n.sup.2 (r)=n.sup.2 (o)[1+G.sub.2 (r/r.sub.o).sup.2 +G.sub.4 (r/r.sub.o).sup.4 ] where n(o) is the refractive index at the center of the core, and G 2 and G 4 the secondary- and fourth-order coefficients representing the distribution of the graded refractive index of the core; and (b) a cladding covering at least a portion of the outer periphery of said core and having a thickness and a refractive index which are determined in accordance with the refractive index at the center of said core, whereby the aberration can be reduced below the diffraction limit of light.
Claim 3
Dependent Claim
32 words
The cladded lens of claim 1, wherein said cladding has an entry side and an exit side and wherein the thickness of said cladding at its entry and exit sides are different.
Claim 4
Dependent Claim
33 words
The cladded lens of claim 1, wherein said cladding has an entry side and an exit side and wherein the refractive index of said cladding at its entry and exit sides are different.
Claim 5
Dependent Claim
36 words
The cladded lens of claim 1, wherein said cladding has an entry side and an exit side and wherein the thickness and the refractive index of said cladding at its entry and exit sides are different.
Claim 6
Dependent Claim
23 words
The cladded lens of claim 1, wherein said core is a hemisphere having a plane portion which is provided with a reflecting means.
References Cited (Backward Citations)
US2213307A
Cited
US2273847A
Cited
GB600005A
Cited
GB664754A
Cited
US3166623A
Cited
US4327963A
Cited
US4268112A
Cited
US4153330A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-12-26 | 1987-06-27 | 1987-12-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-12-26 | 1991-06-27 | 1991-12-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-12-26 | 1995-06-27 | 1995-12-27 | $7700.00 | Window Closed / Lapsed |