Patent US3869197A successfully refreshed from Google Patents.
US3869197A
Expired / Lapsed
US
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Light-deflecting system for effecting bragg diffraction over a wide bandwidth
Assignee: Eastman Kodak Co
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Filing: 1973-07-30
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Granted: 1975-03-04
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Expires: 1993-07-30
Abstract
Abstract A system is described in which a laser beam is diffracted or deflected into at least 1,500 resolvable positions. The system includes an acoustooptic device comprising a block of acoustooptic material, such as lead molybdate, with an array of piezoelectric transducers bonded to one side or surface. In order to acheive operation over a wide bandwidth, it is necessary to steer the direction of propagation of the acoustic wave so that the Bragg diffraction condition is approximately satisfied. This can be accomplished by providing an array of steps which is cut into an edge surface of the acoustooptic block, each step being of a particular width and height which are related to the wavelength of the acoustic wave at the designed frequency of the device. A transducer is bonded to each step, the transducers being serially connected to an oscillator means which generates a series of electrical signals within a predetermined frequency range for causing sound waves to be radiated or propagated by each transducer. Since the transducers are serially connected, they are oppositely poled and radiate in phase. Hence the electrical field direction alternates.
Inventors
- 👤 James C Owens
- 👤 Richard N Blazey
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 14:56
CPC Classifications
G; G02; G02F; G02F1/00; G02F1/29; G02F1/33; G02F1/332
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
317 words
An acoustooptic light deflecting system having an efficiency greater than a minimum predetermined efficiency and operable with respect to the center frequency of a predetermined bandwidth, comprising: means for generating a beam of monochromatic light that is relatively narrow in width as compared to length and for directing the beam along a prescribed path; oscillator means for generating an electrical signal of a preselected frequency that is generally within the bandwidth; an acoustooptic medium responsive to a constant acoustical power and having center frequency that is offset with respect to the bandwidth center frequency, spaced, parallel incident and exit side surfaces and spaced, parallel ends, the medium being positioned in the prescribed path with the light beam intersecting the incident side surface at an angle to effect Bragg diffraction of the light beam and being displaced relative to the prescribed path in a direction to optimize the efficiency and resolution of the system; transducer means comprising a number of piezoelectric elements, each of generally rectilinear shape, bonded to one end in spaced-apart relation and extending generally in the direction of the path, and phasing means associated with each of the elements for radiating the latter in phase, the elements providing an array, having a resonance frequency that is offset relative to the bandwidth centeR frequency and being responsive to the selected frequency for generating a number of series of acoustic waves in the medium in accordance with the number of elements; and matching circuitry having an offset center frequency for electrically balancing and interconnecting the oscillator means and piezoelectric elements, whereby the incident beam is diffracted at a different angle by each series of waves to produce a diffracted light beam uniquely associated with the selected frequency, and whereby the offset of the center frequency of the medium, the array and the matching circuitry increases the efficiency over and above that greater than the minimum predetermined efficiency.
Claim 2
Dependent Claim
317 words
An acoustooptic light deflecting system having an efficiency greater than a minimum predetermined efficiency and operable with respect to the center frequency of a predetermined bandwidth, comprising: means for generating a beam of monochromatic light that is relatively narrow in width as compared to length and for directing the beam along a prescribed path; oscillator means for generating an electrical signal of a preselected frequency that is generally within the bandwidth; an acoustooptic medium responsive to a constant acoustical power and having center frequency that is offset with respect to the bandwidth center frequency, spaced, parallel incident and exit side surfaces and spaced, parallel ends, the medium being positioned in the prescribed path with the light beam intersecting the incident side surface at an angle to effect Bragg diffraction of the light beam and being displaced relative to the prescribed path in a direction to optimize the efficiency and resolution of the system; transducer means comprising a number of piezoelectric elements, each of generally rectilinear shape, bonded to one end in spaced-apart relation and extending generally in the direction of the path, and phasing means associated with each of the elements for radiating the latter in phase, the elements providing an array, having a resonance frequency that is offset relative to the bandwidth centeR frequency and being responsive to the selected frequency for generating a number of series of acoustic waves in the medium in accordance with the number of elements; and matching circuitry having an offset center frequency for electrically balancing and interconnecting the oscillator means and piezoelectric elements, whereby the incident beam is diffracted at a different angle by each series of waves to produce a diffracted light beam uniquely associated with the selected frequency, and whereby the offset of the center frequency of the medium, the array and the matching circuitry increases the efficiency over and above that greater than the minimum predetermined efficiency.
Claim 3
Dependent Claim
360 words
An acoustooptic light-deflecting system having an efficiency greater than a minimum predetermined efficiency and operable with respect to the center frequency of a predetermined bandwidth, comprising: means for generating a beam of monochromatic light that is relatively narrow in width as compared to length and for directing the beam along a prescribed path; oscillator means for generating an electrical signal of a preselected frequency that is generally within the bandwidth; an acoustooptic medium responsive to a constant acoustical power and having a center frequency that is offset with respect to the bandwidth center frequency, spaced, parallel side surfaces and at one end thereof having a series of steps extending generally in the direction of the path, the faces of the steps being generally parallel to each other and perpendicular to each of the respective side surfaces, the displacement of each face relative to the next face being a full wavelength as related to the bandwidth center frequency, the medium being positioned in the prescribed path with the light beam incident on one of the side surfaces at an angle to effect Bragg diffraction of the light beam and being displaced relative to the prescribed path in a direction to optimize the efficiency and resolution of the system; transducer means comprising a piezoelectric element of generally rectilinear shape bonded to the face of each step and in spaced relation to the step adjacent thereto, the elements providing an array, having a resonance frequency that is offset relative to the bandwidth center frequency and being responsive to the selected frequency for generating a number of series of acoustic waves in the medium in accordance with the number of elements; and matching circuitry having an offset center frequency for electrically balancing and interconnecting the oscillator means and piezoelectric elements, whereby the latter radiate in phase so that the incident beam is diffracted at a different angle by each series of waves to produce a diffracted light beam uniquely associated with the selected frequency, and whereby the offset of the center frequency of the medium, the array and the matching circuitry increases the efficiency over and above that greater than the minimum predetermined efficiency.
Claim 4
Dependent Claim
360 words
An acoustooptic light-deflecting system having an efficiency greater than a minimum predetermined efficiency and operable with respect to the center frequency of a predetermined bandwidth, comprising: means for generating a beam of monochromatic light that is relatively narrow in width as compared to length and for directing the beam along a prescribed path; oscillator means for generating an electrical signal of a preselected frequency that is generally within the bandwidth; an acoustooptic medium responsive to a constant acoustical power and having a center frequency that is offset with respect to the bandwidth center frequency, spaced, parallel side surfaces and at one end thereof having a series of steps extending generally in the direction of the path, the faces of the steps being generally parallel to each other and perpendicular to each of the respective side surfaces, the displacement of each face relative to the next face being a full wavelength as related to the bandwidth center frequency, the medium being positioned in the prescribed path with the light beam incident on one of the side surfaces at an angle to effect Bragg diffraction of the light beam and being displaced relative to the prescribed path in a direction to optimize the efficiency and resolution of the system; transducer means comprising a piezoelectric element of generally rectilinear shape bonded to the face of each step and in spaced relation to the step adjacent thereto, the elements providing an array, having a resonance frequency that is offset relative to the bandwidth center frequency and being responsive to the selected frequency for generating a number of series of acoustic waves in the medium in accordance with the number of elements; and matching circuitry having an offset center frequency for electrically balancing and interconnecting the oscillator means and piezoelectric elements, whereby the latter radiate in phase so that the incident beam is diffracted at a different angle by each series of waves to produce a diffracted light beam uniquely associated with the selected frequency, and whereby the offset of the center frequency of the medium, the array and the matching circuitry increases the efficiency over and above that greater than the minimum predetermined efficiency.
Claim 5
Dependent Claim
52 words
An acoustooptic light deflecting system in accordance with claim 2 including acoustic wave absorbing means fixed to the other end of the medium, the displacement of the medium being in a direction such that the incident light beam is effectively closer to the absorbing means for optimizing the resolution of the system.
Claim 6
Dependent Claim
40 words
An acoustooptic light-deflecting system in accordance with claim 2 wherein the displacement of the medium is in a direction such that the incident light beam is effectively closer to the series of steps for optimizing the efficiency of the system.
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) | 1978-03-03 | 1978-09-02 | 1979-03-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-03-03 | 1982-09-02 | 1983-03-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-03-03 | 1986-09-02 | 1987-03-04 | $7700.00 | Window Closed / Lapsed |