US3909113A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Optical coupler
Assignee: United States Department of the Navy
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Filing: 1974-05-01
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Granted: 1975-09-30
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Expires: 1994-05-01
Abstract
Abstract The circular dichroism exhibited by cholesteric liquid materials is employed to couple light having selected determinable wavelength and circular polarization out of an optical path. Thin films of selected cholesteric liquid crystal materials are interposed in an optical path so that the circular dichroism of the liquid crystal materials causes scattering of light energy having a particular combination of wavelength and circular polarization which is characteristic of the properties of each such material. Light energy which is not within the affected wavelength and circular polarization combinations is transmitted along the optical path without significant attenuation. The scattered light is coupled out of the optical path where it may be suitably detected for signal information content. The coupler may be rendered tunable by impressing an electric field across the cholesteric liquid crystal material to change the helical pitch of its molecular alignment, causing a commensurate change in the wavelength of light energy which will be scattered.
Inventors
- 👤 Larry B Stotts
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 21:55
CPC Classifications
G; G02; G02F; G02F1/00; G02F1/01; G02F1/13; G02F1/1326; G02B; G02B5/00; G02B5/30; G02B5/3016
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
218 words
An optical coupler for transferring light energy of selected wavelength and circular polarization comprising: an optical path comprising light conducting means capable of transmitting light energy including said selected wavelength and circular polarization along a determinable principal optical axis; a source of light of said selected wavelength and circular polarization and means for directing said light along said axis; a thin film of cholesteric liquid crystal material disposed in said optical path substantially perpendicular thereto to intercept said principal optical axis, said material having a homogeneous molecular alignment defined by a determinable helical pitch and direction coinciding with said selected wavelength and circular polarization, respectively, for laterally scattering light energy of said selected wavelength and circular polarization; transparent electrodes disposed one on each side of said thin film of cholesteric liquid crystal material; and a source of variable electrical potential arranged for connection across said electrodes, whereby to cause selective variations of the molecular alignment of said cholesteric liquid crystal material from said determinable pitch and direction for rendering it selectively responsive to laterally scatter different wavelengths of light energy commensurate with said selective variations; and photo-responsive means disposed parallel to said principal optical axis adjacent said light conducting means and said cholerestic liquid crystal material to receive light energy laterally scattered by said cholesteric liquid crystal material.
Claim 2
Dependent Claim
218 words
An optical coupler for transferring light energy of selected wavelength and circular polarization comprising: an optical path comprising light conducting means capable of transmitting light energy including said selected wavelength and circular polarization along a determinable principal optical axis; a source of light of said selected wavelength and circular polarization and means for directing said light along said axis; a thin film of cholesteric liquid crystal material disposed in said optical path substantially perpendicular thereto to intercept said principal optical axis, said material having a homogeneous molecular alignment defined by a determinable helical pitch and direction coinciding with said selected wavelength and circular polarization, respectively, for laterally scattering light energy of said selected wavelength and circular polarization; transparent electrodes disposed one on each side of said thin film of cholesteric liquid crystal material; and a source of variable electrical potential arranged for connection across said electrodes, whereby to cause selective variations of the molecular alignment of said cholesteric liquid crystal material from said determinable pitch and direction for rendering it selectively responsive to laterally scatter different wavelengths of light energy commensurate with said selective variations; and photo-responsive means disposed parallel to said principal optical axis adjacent said light conducting means and said cholerestic liquid crystal material to receive light energy laterally scattered by said cholesteric liquid crystal material.
Claim 3
Dependent Claim
26 words
An optical coupler as claimed in claim 1 wherein said photo-responsive means is operative to develop signals as a function of received laterally scattered light energy.
Claim 4
Dependent Claim
25 words
An optical coupler as claimed in claim 1 wherein said cholesteric liquid crystal material is positioned between abutting ends of material comprising said optical path.
Claim 5
Dependent Claim
50 words
A plurality of optical couplers as claimed in claim 1, each coupler comprising a thin film of cholesteric liquid crystal material disposed contiguous to said optical path at a different section and having a determinable helical pitch and direction coinciding with a different combination of selected wavelength and circular polarization.
Claim 6
Dependent Claim
45 words
A plurality of optical couplerS as claimed in claim 4 and including means for transmitting light signals of selected wavelength and circular polarization combination along said optical path for transferring signal information only to optical couplers responsive to said selected wavelength and circular polarization combinations.
References Cited (Backward Citations)
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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) | 1978-09-29 | 1979-03-31 | 1979-09-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-09-29 | 1983-03-31 | 1983-09-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-09-29 | 1987-03-31 | 1987-09-30 | $7700.00 | Window Closed / Lapsed |