US3642375A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Optical combiner
Assignee: Unisys Corp
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Filing: 1969-10-02
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Granted: 1972-02-15
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Expires: 1989-10-02
Abstract
Abstract Apparatus for determining the magnitude and sense of the frequency difference between two identically sensed circularly polarized light beams comprising a beam splitter and respective pairs of analyzers and photodetectors. The light beams impinge on the beam splitter such that the transmitted component of one beam and the reflected component of the other beam are directed through one analyzer onto a related photodetector while the reflected component of the one beam and the transmitted component of the other are directed through the other analyzer and its related photodetector, the transmission axes of the analyzers being angularly displaced relative to one another whereby electrical signals provided by the photodetectors are proportionately phase-shifted relative to one another.
Inventors
- 👤 Warren M Macek
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 22:06
CPC Classifications
G; G01; G01S; G01S17/00; G01S17/02; G01S17/50; G01N; G01N21/00; G01N21/17; G01N21/21
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
300 words
An optical combiner adapted to receive two identically sensed circularly polarized light beams for producing phase-shifted electrical signals having a frequency proportional to the frequency difference between said two light beams and relative phase representative of the sense of the frequency difference therebetween, said apparatus comprising first and second optical analyzers arranged such that the transmission axis of the first analyzer is angularly displaced from the transmission axis of the second analyzer, beam splitter means disposed in the path of said circularly polarized light beams for partially transmitting and partially reflecting each beam such that at least part of the energy in both a reflected component of one beam and a transmitted component of the other beam is applied to the first analyzer and at least part of the energy in both a transmitted component of said one beam and a reflected component of said other beam is applied to the second analyzer, a first optical frequency mixer positioned to receive the light signal transmitted through the first analyzer and a second optical frequency mixer positioned to receive the light signal transmitted through the second analyzer, said optical frequency mixers being operative to convert the light signals incident thereon to equivalent electrical signals phase shifted relative to one another in proportion to the angular displacement between the transmission axes of the analyzers, means responsive to said electrical signals for determining the occurrence of zero crossings thereof and providing timing signals corresponding to said zero crossings, and means responsive to a timing signal corresponding to a zero crossing of the electrical signal derived from the first optical frequency mixer and further responsive to a timing signal corresponding to a zero crossing of the electrical signal derived from the second optical frequency mixer for determining the time interval between said timing signals.
Claim 2
Dependent Claim
300 words
An optical combiner adapted to receive two identically sensed circularly polarized light beams for producing phase-shifted electrical signals having a frequency proportional to the frequency difference between said two light beams and relative phase representative of the sense of the frequency difference therebetween, said apparatus comprising first and second optical analyzers arranged such that the transmission axis of the first analyzer is angularly displaced from the transmission axis of the second analyzer, beam splitter means disposed in the path of said circularly polarized light beams for partially transmitting and partially reflecting each beam such that at least part of the energy in both a reflected component of one beam and a transmitted component of the other beam is applied to the first analyzer and at least part of the energy in both a transmitted component of said one beam and a reflected component of said other beam is applied to the second analyzer, a first optical frequency mixer positioned to receive the light signal transmitted through the first analyzer and a second optical frequency mixer positioned to receive the light signal transmitted through the second analyzer, said optical frequency mixers being operative to convert the light signals incident thereon to equivalent electrical signals phase shifted relative to one another in proportion to the angular displacement between the transmission axes of the analyzers, means responsive to said electrical signals for determining the occurrence of zero crossings thereof and providing timing signals corresponding to said zero crossings, and means responsive to a timing signal corresponding to a zero crossing of the electrical signal derived from the first optical frequency mixer and further responsive to a timing signal corresponding to a zero crossing of the electrical signal derived from the second optical frequency mixer for determining the time interval between said timing signals.
Claim 3
Dependent Claim
72 words
The apparatus of claim 1 wherein said time interval determining means includes a clock pulse source, switching means connected to the clock pulse source, said switching means being responsive to said timing signals derived from the first and second optical frequency mixers for closing and opening said switching means, and a counter coupled to said switching means to receive clock pulses transmitted therethrough during the interval when said switching means is closed.
Claim 4
Dependent Claim
263 words
An optical system for operating on two identically sensed circularly polarized input light beams to produce phase-shifted electrical signals having a frequency proportional to the frequency difference between the two input beams and a rElative phase representative of the sense of the frequency difference therebetween, said system comprising means for providing a pair of identically sensed circularly polarized input light beams, beam splitter means disposed in the path of the circularly polarized input beams for partially transmitting and partially reflecting each beam to produce first and second composite beams each containing a component of both input beams, the polarization sense of the transmitted components being retained while the polarization sense of the reflected parts is reversed whereby the respective transmitted and reflected components of each composite beam are of opposite circular polarization sense relative to one another, first and second optical analyzers positioned in the path of the first and second composite beams respectively, the transmission axes of said analyzers being angularly displaced relative to one another whereby, under a condition where said input beams are at different frequencies, the plane-polarized beams transmitted through the analyzers are amplitude modulated and phase shifted relative to one another and the frequency of the amplitude modulated beams is proportional to the frequency difference between the input beams, first and second optical frequency mixers positioned to receive the amplitude-modulated plane-polarized beams transmitted through said first and second analyzers respectively and convert said plane-polarized beams to equivalent electrical signals phase shifted relative to one another in proportion to the angular displacement between the transmission axes of said analyzers.
Claim 5
Dependent Claim
263 words
An optical system for operating on two identically sensed circularly polarized input light beams to produce phase-shifted electrical signals having a frequency proportional to the frequency difference between the two input beams and a rElative phase representative of the sense of the frequency difference therebetween, said system comprising means for providing a pair of identically sensed circularly polarized input light beams, beam splitter means disposed in the path of the circularly polarized input beams for partially transmitting and partially reflecting each beam to produce first and second composite beams each containing a component of both input beams, the polarization sense of the transmitted components being retained while the polarization sense of the reflected parts is reversed whereby the respective transmitted and reflected components of each composite beam are of opposite circular polarization sense relative to one another, first and second optical analyzers positioned in the path of the first and second composite beams respectively, the transmission axes of said analyzers being angularly displaced relative to one another whereby, under a condition where said input beams are at different frequencies, the plane-polarized beams transmitted through the analyzers are amplitude modulated and phase shifted relative to one another and the frequency of the amplitude modulated beams is proportional to the frequency difference between the input beams, first and second optical frequency mixers positioned to receive the amplitude-modulated plane-polarized beams transmitted through said first and second analyzers respectively and convert said plane-polarized beams to equivalent electrical signals phase shifted relative to one another in proportion to the angular displacement between the transmission axes of said analyzers.
Claim 6
Dependent Claim
131 words
The apparatus of claim 3 further including first additional beam splitter means disposed in the path of the composite beams directed from said beam splitter means to said first analyzer, and second additional beam splitter means disposed in the path of the composite beams directed from said beam splitter means to said second analyzer, said first additional beam splitter means being operative to direct part of the light incident thereon to said first analyzer and part to a third analyzer, said second additional beam splitter means being operative to direct part of the light incident thereon to said second analyzer and part to a fourth analyzer, and said third and fourth analyzers being oriented with their transmission axes angularly displaced relative to both one another and said first and second analyzers.
Claim 7
Dependent Claim
33 words
The apparatus of claim 3 including an electrical phase shift device connected to the output of one of said optical frequency mixers to impart a predetermined phase shift to the signal provided therefrom.
Claim 8
Dependent Claim
27 words
The apparatus of claim 5 wherein the transmission axis of said first analyzer is angularly displaced from the transmission axis of said second analyzer by 45* .
Claim 9
Dependent Claim
51 words
The apparatus of claim 8 wherein said beam splitter means is oriented in the path of said two circularly polarized beams such that the reflected and transmitted beam components directed to the first analyzer are collinearly aligned, and likewise for the transmitted and reflected beam components directed to the second analyzer.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-02-14 | 1975-08-16 | 1976-02-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-02-14 | 1979-08-16 | 1980-02-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-02-14 | 1983-08-16 | 1984-02-15 | $7700.00 | Window Closed / Lapsed |