Patent US833745A successfully refreshed from Google Patents.
Patent US3600611A successfully refreshed from Google Patents.
US3600611A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Elasto-optic device with mechanical bias
Assignee: Kettering Scientific Research Inc
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Filing: 1970-03-18
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Granted: 1971-08-17
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Expires: 1990-03-18
Abstract
Abstract A device for modulating the intensity of a beam of light includes a pair of polarizing filters, the polarization plane angles of which are crossed, and a fused quartz light transmitting element mounted between the polarizing filters with its preferred axis oriented at 45* to the filters. The element is made to exhibit birefringence by mechanical stress imposed by a piezoelectric device mechanically attached to one side of the element. A second piezoelectric device is attached to the other side of the element, and supplies an output to control the frequency of an oscillator circuit to maintain the frequency of oscillation of the assembly at resonance. The light transmitting element and the piezoelectric devices are mounted in a metal ring which is provided with an adjustment so that mechanical force may be applied to the element through the piezoelectric devices to bias the element thereby producing a quarter wave retardation which improves the efficiency of the device.
Inventors
- 👤 Richard W Treharne
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 14:22
CPC Classifications
G; G02; G02F; G02F1/00; G02F1/01; G02F1/0128; G02F1/0131; G02B; G02B27/00; G02B27/28; G02B27/281
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
161 words
In apparatus for modulating the intensity of a beam of light including first and second polarizing filters mounted in optical alignment for the transmission of light therethrough, one of said filters having its polarization plane angle at 90* to the other said filter, a birefringent light modulating element mounted in the light path between said filters, modulating means mounted in contact with said element to transmit mechanical energy thereinto to vary the birefringence of said element, and energy detecting means mounted in contact with said element on the side opposite said modulating means for generating a signal responsive to the energy transmitted through said element by said modulating means for use in maintaining a frequency of oscillation of said apparatus at resonance, the improvement comprising means for applying an average mechanical pressure to said element through said modulating means and said detecting means to bias said element to approximate one-quarter wavelength retardation thereby to maximize the modulation efficiency of said apparatus.
Claim 2
Dependent Claim
161 words
In apparatus for modulating the intensity of a beam of light including first and second polarizing filters mounted in optical alignment for the transmission of light therethrough, one of said filters having its polarization plane angle at 90* to the other said filter, a birefringent light modulating element mounted in the light path between said filters, modulating means mounted in contact with said element to transmit mechanical energy thereinto to vary the birefringence of said element, and energy detecting means mounted in contact with said element on the side opposite said modulating means for generating a signal responsive to the energy transmitted through said element by said modulating means for use in maintaining a frequency of oscillation of said apparatus at resonance, the improvement comprising means for applying an average mechanical pressure to said element through said modulating means and said detecting means to bias said element to approximate one-quarter wavelength retardation thereby to maximize the modulation efficiency of said apparatus.
Claim 3
Dependent Claim
51 words
The apparatus of claim 1 further including circuit means having an output connected to said modulating means and an input responsive to the output from said detecting means, said circuit means maintaining the frequency of modulation of said element at or near its resonant frequency to provide the highest mOdulation efficiency.
Claim 4
Dependent Claim
38 words
The apparatus of claim 1 wherein said birefringent light modulating element is fused quartz and wherein said element is mounted with its preferred axis orientated at 45* to the polarization angle of said first and second polarizing filters.
Claim 5
Dependent Claim
31 words
The apparatus of claim 1 for use with visible light wherein said element is mechanically biased to produce a one-quarter wave retardation in the range of 5,400 A. to 5,800 A.
Claim 6
Dependent Claim
42 words
The apparatus of claim 1 further including shock absorbing pads placed between said modulating means and said detecting means, the mechanical pressure to bias said element being applied through said pads and said modulating means and said detecting means to said element.
Claim 7
Dependent Claim
88 words
Apparatus for modulating a birefringent light transmitting element including modulating means mechanically attached to said element for modulating said element at or near its resonant frequency, and detecting means mounted in contact with said element on the side opposite said modulating means for generating a signal in response to the mechanical energy transmitted through said element, the improvement comprising means for applying pressure to said element through said modulating means and said detecting means to bias said element mechanically to approximate one-quarter wave retardation at a selected wavelength.
Claim 8
Dependent Claim
88 words
Apparatus for modulating a birefringent light transmitting element including modulating means mechanically attached to said element for modulating said element at or near its resonant frequency, and detecting means mounted in contact with said element on the side opposite said modulating means for generating a signal in response to the mechanical energy transmitted through said element, the improvement comprising means for applying pressure to said element through said modulating means and said detecting means to bias said element mechanically to approximate one-quarter wave retardation at a selected wavelength.
Claim 9
Dependent Claim
14 words
The apparatus of claim 6 wherein said modulating and detecting means are piezoelectric devices.
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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) | 1974-08-16 | 1975-02-15 | 1975-08-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-08-16 | 1979-02-15 | 1979-08-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-08-16 | 1983-02-15 | 1983-08-17 | $7700.00 | Window Closed / Lapsed |