Patent US4335933A successfully refreshed from Google Patents.
US4335933A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Fiber optic wavelength demultiplexer
Assignee: Hughes Missile Systems Co
•
Filing: 1980-06-16
•
Granted: 1982-06-22
•
Expires: 2000-06-16
Abstract
Abstract An optical fiber wavelength demultiplexer including an optical fiber mounted and adhered to a curved surface having a clad single fiber core, a planar surface extending partially into and along the fiber through the cladding, a prism mounted on the surface having a reflective diffraction grating surface positioned to receive signals from the fiber travelling in one direction and demultiplex such signals, and an array of photodiodes mounted adjacent the prism to receive the demultiplexed signals.
Inventors
- 👤 John P. Palmer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 19:50
CPC Classifications
G; G02; G02B; G02B6/00; G02B6/24; G02B6/26; G02B6/28; G02B6/293; G02B6/29304; G02B6/29316; G02B6/29317; G02B6/29379; G02B6/2938; G02B6/42; G02B6/4201; G02B6/4256; G02B6/4257; G02B6/4259; G02B6/4286; G02B6/4287
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
200 words
A fiber optic directional demultiplexer for tapping off predetermined portions of wavelength optical energy from a single optical fiber and demultiplexing the optical energy comprising: a curved form for supporting an optical fiber and shaping a portion thereof to a predetermined segment of a circle; a single optical fiber mounted on said form; means for affixing the optical fiber along a portion thereof to the curved portion of the form of a selected radius of curvature, the fiber and affixing means in the center section of the curved portion of the fiber being lapped and polished to a preselected depth of penetration into the fiber to develop a planar surface; prism means having a face of a predetermined characteristic angle affixed to said planar surface in contact with the optical fiber and affixed thereto by means of an optically transparent adhesive; light diffracting means formed on said prism face in line with the path of multiplexed light coupled from the fiber to the prism and effective to reflect and diffract selected portions of said light; and photosensitive means having plural photosensitive elements positioned adjacent said prism to respond selectively to different wavelengths of light directed from the light diffracting means.
Claim 2
Dependent Claim
200 words
A fiber optic directional demultiplexer for tapping off predetermined portions of wavelength optical energy from a single optical fiber and demultiplexing the optical energy comprising: a curved form for supporting an optical fiber and shaping a portion thereof to a predetermined segment of a circle; a single optical fiber mounted on said form; means for affixing the optical fiber along a portion thereof to the curved portion of the form of a selected radius of curvature, the fiber and affixing means in the center section of the curved portion of the fiber being lapped and polished to a preselected depth of penetration into the fiber to develop a planar surface; prism means having a face of a predetermined characteristic angle affixed to said planar surface in contact with the optical fiber and affixed thereto by means of an optically transparent adhesive; light diffracting means formed on said prism face in line with the path of multiplexed light coupled from the fiber to the prism and effective to reflect and diffract selected portions of said light; and photosensitive means having plural photosensitive elements positioned adjacent said prism to respond selectively to different wavelengths of light directed from the light diffracting means.
Claim 3
Dependent Claim
21 words
The device of claim 1 wherein the photosensitive means is cemented to the prism by means of an optically transparent adhesive.
Claim 4
Dependent Claim
37 words
The device of claim 1 wherein the photosensitive means is separate from the prism and mounted adjacent thereto so that light passing through the prism and reflected by the diffracting means is directed to the photosensitive means.
Claim 5
Dependent Claim
42 words
The device of claim 1 further comprising a pair of optical connectors coupled to opposite ends of the fiber, circuit means incorporated in the photosensitive means, and an enclosure supporting the form, the photosensitive means and the circuit means in operative relationship.
Claim 6
Dependent Claim
23 words
The device of claim 4 wherein the circuit means further comprises a preamplifier stage integrated with said photosensitive elements in a single unit.
Claim 7
Dependent Claim
35 words
The device of claim 1 wherein the radius of curvature of the curved portion of the form and a portion of the optical fiber affixed thereto is selected to be between 5 and 8 cm.
Claim 8
Dependent Claim
14 words
The device of claim 6 wherein the selected radius of curvature is 6 cm.
Claim 9
Dependent Claim
13 words
The device of claim 1 wherein the material of the form is aluminum.
Claim 10
Dependent Claim
18 words
The device of claim 1 wherein the characteristic angle of the prism face is selected to be 52°+/-5°.
Claim 11
Dependent Claim
11 words
The device of claim 9 wherein the characteristic angle is 52°.
Claim 12
Dependent Claim
21 words
The device of claim 1 wherein an optical filter is positioned between the planar surface of the fiber and the prism.
Claim 13
Dependent Claim
14 words
The device of claim 1 wherein said light diffracting means comprises an optical grating.
Claim 14
Dependent Claim
24 words
The device of claim 12 wherein said grating comprises a metallic surface deposited on said prism face and selectively etched to form said grating.
Claim 15
Dependent Claim
14 words
The device of claim 12 wherein said grating is blazed into said prism face.
Claim 16
Dependent Claim
26 words
The device of claim 12 wherein the pitch of said grating is selected to be over one-half of the wavelength of the light to be diffracted.
Claim 17
Dependent Claim
19 words
The device of claim 12 wherein the grating is cemented to the prism face using an optically transparent adhesive.
Claim 18
Dependent Claim
25 words
The device of claim 1 wherein the characteristic angle of the prism face is selected to diffract higher order diffracted signals to the photosensitive means.
Claim 19
Dependent Claim
18 words
The device of claim 1 wherein the photosensitive means includes means to absorb signals that are not diffracted.
References Cited (Backward Citations)
US4136929A
Cited
JPS5224539A
Cited
US4089584A
Cited
US4111524A
Cited
JPS5413347A
Cited
US4153330A
Cited
JPS54118255A
Cited
US4301543A
Cited
US4307933A
Cited
US4317614A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1985-06-21 | 1985-12-21 | 1986-06-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-06-21 | 1989-12-21 | 1990-06-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-06-21 | 1993-12-21 | 1994-06-22 | $7700.00 | Window Closed / Lapsed |