US3759603A - Acousto-optical light deflector having increased band width and short access time - Google Patents

Acousto-optical light deflector having increased band width and short access time Download PDF

Info

Publication number
US3759603A
US3759603A US00201652A US3759603DA US3759603A US 3759603 A US3759603 A US 3759603A US 00201652 A US00201652 A US 00201652A US 3759603D A US3759603D A US 3759603DA US 3759603 A US3759603 A US 3759603A
Authority
US
United States
Prior art keywords
transducers
acousto
optical light
crystal
frequency
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US00201652A
Other languages
English (en)
Inventor
H Eschler
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Siemens AG
Siemens Corp
Original Assignee
Siemens Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Siemens Corp filed Critical Siemens Corp
Application granted granted Critical
Publication of US3759603A publication Critical patent/US3759603A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • G—PHYSICS
    • G02—OPTICS
    • G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
    • G02F1/29—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the position or the direction of light beams, i.e. deflection
    • G02F1/33—Acousto-optical deflection devices
    • G02F1/332—Acousto-optical deflection devices comprising a plurality of transducers on the same crystal surface, e.g. multi-channel Bragg cell

Definitions

  • ABSTRACT An acousto-optical light deflector employs a crystal as a sound medium which is energized by way of a piezoelectric trandsducer with ultrasonic waves to deflect a light beam incident approximately parallel with the sound wave fronts as a function of the ultrasonic frequency.
  • the deflector also comprises a control apparatus for supplying the piezo-electric transducer with a controllable variable frequency and is charactrized by the provision of several piezo-electric transducers which are designed for consecutive frequency ranges and which are juxtaposed on the sound medium.
  • This invention relates to a light deflector having several transducers for consecutive frequency ranges arranged in juxtaposition, and further relates to an acousto-optical light deflector comprising a crystal which is utilized as a sound medium and which is energized by way of a piezo-electric converter with ultrasonic waves to deflect a light ray incident approximately parallel with the wave fronts as a function of the ultrasonic frequency, and also to control apparatus for supplying the piezo-electric transducer with a controllable variable frequency.
  • the angle of diffraction therefore depends on the distance of the pressure maxima, that is, however, on the wave length and/or the frequency of the ultrasonic wave. If the direction of incidence of the light ray against the wave front is inclined by a small angle, a Bragg reflection of the light ray can be observed at the wave fronts. In order for a Bragg reflection to occur, however, the angle of incidence must suffice for the Bragg condition.
  • the frequency bandwidth and the so-called capacity speed product (CSP) connected therewith of acoustooptical light deflectors are limited by the varying sonic radiation output of the piezoelectric transducers at dif- 2 ferent frequencies and the solid direction of incidence (Bragg condition). Therefore, the bandwidth of the known acousto-optical light deflectors has been limited to a maximum of about one octave.
  • Acousto-optical light deflectors are utilized where a rapid light deflection is important.
  • the deflectability of the light ray should be provided up to large angles of deflection, which corresponds to an effective approachability of the deflection crystal having a large bandwidth.
  • the primary object of the present invention is to provide an increase in the number of deflection angles and to increase for that purpose the bandwidth of an acousto-optical deflector to a range encompassing more than one octave.
  • the foregoing objective is achieved through the provision of several piezoelectric transducers which are designed for consecutive frequency ranges and juxtaposed on a sound medium, the transducers increasing the sound frequency bandwidth to values up to 300 MHZ and maintaining the deflection efficiency effectively constant over a larger range than heretofore known.
  • the crystal plates used as piezo-electric transducers are preferably arranged at an angle on the sound medium so that the deflection of the incident light ray can remain stable.
  • the piezo-electric transducers may also be advantageously arranged in a partial area of a phased array, that is, instead of being tilted with respect to each other, they may be arranged juxtaposed and parallel and electrically series connected to a variable oscillator.
  • transducers from such different crystal materials so that the amplitudes radiated by the transducers are aligned with each other.
  • the transducers are preferably dimensioned in such a manner that the frequencies coincide, for which in case of two adjacent frequencies, the deflection efficiency drops to half the maximum value. The degree of deflection effect is then actually constant over a major frequency range.
  • a control apparatus may advantageously be provided with an oscillator of a fixed frequency and with an oscillator of variable frequency, as well as with a mixing device in which the fixed and the variable frequencies are superposed in order to obtain the control frequencies.
  • Another possibility resides in the control apparatus being provided with a number of oscillators whose frequencies are invariable and connected by way of electronic switches and a bus bar arrangement with one or several transducers.
  • the entire frequency range is advantageously divided into octaves by supplying the frequencies of different octaves to separate bus bars which are provided with low pass filters.
  • the transducers should be connected with the crystal utilized as a sonic medium, preferably by cold pressing, in vacuum, under the interposition of compounds having a low melting point, such as indium, thalium, etc.
  • FIG. I is a pictorial and schematic representation of an acousto-optical light deflector having increased bandwidth
  • FIG. 2 is a graphical illustration of the total deflection efficiency effect of the multiple transducer deflector
  • FIG. 3 illustrates a phased array design of an acoustooptical deflector
  • FIG. 4 is a block diagram illustration of an oscillator which is synchronizable throughout the entire frequency range.
  • FIG. 5 is a block diagram representation for a digitalized control of the transducers.
  • a deflector crystal 1 is illustrated as a sound medium.
  • the deflector crystal 1 carries three acoustic transducers 2, 3 and 4 with different frequency ranges of the sound radiation, namely, fl to f2, f2 to f3, and f3 to f4.
  • the three transducers 2, 3 and 4 may be connected in parallel and connected to a high frequency oscillator 5.
  • Each transducer actually represents a band-pass filter and accommodates an electrical output only in its corresponding frequency band.
  • the transducers deliver the absorbed energy to the deflection crystal in the form of ultrasonic waves, whereby compressions 6 are produced in the deflection crystal.
  • the distance of the illustrated compression lines corresponds to the wave lengths of the ultrasonic waves. If a laser beam enters the deflection crystal 1 from a fixed predetermined direction, it is deflected at the wave fronts 6 according to the Bragg condition. The incident laser beam 7 is deflected, depending on the ultrasonic frequency present, into the direction 8, 9 or 10.
  • the number of possible directions of deflection of the laser beam is a function of the number of acousto-optical transducers and their usable frequency bandwidths.
  • the scale for the efficiency of the light deflector is the so-called capacity speed product CSP. It is only a function of the bandwidth of the deflector and the expression Af/2 applied. With the structure described, bandwidths between lOO and 300 MHz and capacity speed products of about 2 X 10' seconds are possible.
  • FIG. 2 is a graphical illustration of the degree of deflection effect 1; with respect to the frequency f.
  • the degree of effect is understood to mean the relation of deflected to incidence luminous intensity.
  • FIG. 2 illustrates that each of the three transducers 2, 3 and 4 has a respective degree of effect of 1) l, n 2 and/or 7 3, which has a maximum value at the corresponding central frequencies fl, f2 and f3.
  • the degrees of effect drop off on both sides of these central frequencies.
  • the central frequencies fl, f2 and [3 are spaced such that the degrees of effect bisect where they have dropped by three decibels. From these three curves, a total degree of effect of n, 1; l 17 2 1 3, as represented in the drawing.
  • the degree of effect of a transducer is a function of the data of the sound medium, the light wavelength of the incident beam, the dimensions of the transducer and the sound or sonic performance. At suf- 4 ficiently high sonic performance, percent of the radiated light can be deflected, because no performance is lost under the alternating effect of the light waves with the sonic field.
  • FIG. 3 The manner of operation of a phased array design is illustrated in FIG. 3.
  • the crystal 1 is employed as a sonic medium and carries three transducers 2, 3 and 4 which are juxtaposed parallel with each other.
  • the transducers are electrically seriesconnected with a variable oscillator 5, so that at a time when the transducer 3 causes at a certain distance a compression 36 in the crystal, compressions 37 and 38 shifted by A /2 are generated by the transducers 2 and 4.
  • the compressions 36, 37 and 38 can be consolidated into a single compression line 39 extending obliquely in the crystal. In this way compressions extending obliquely and shifted by A are produced in the crystal, whose oblique position depends on the oscillator frequency.
  • FIG. 4 illustrates how a variable control of the transducers is made possible with a fixed and a variable oscillator.
  • an oscillator 10 has a fixed frequency fa and a variable oscillator l 1 provides frequencies of fb and fa, whereby the frequency fb is greater than the frequency fa. Both frequencies are superposed in a mixer 12 and supplied to the transducers by way of a low pass filter 13 for frequencies which are less than fc-fa and by way of a broad band amplifier 14.
  • the low pass filter 13 is utilized to eliminate the upper frequency waves from influencing the deflection of the luminous beam.
  • FIG. 5 illustrates a block circuit diagram for a digitalized approach for energizing the transducers.
  • the oscillators 15, 16 and 17 have separate fixed frequenciesfl5,fl6 and fl7, respectively, and are consolidated by way of a bus bar 22 as a first group of oscillators
  • the oscillators 18, 19, 20 and 21 have fixed frequencies fl8,f19, j20 and 121, respectively, which are consolidated by means of a bus bar 23 as a second group of oscillators.
  • One frequency octave is contained in each group.
  • a desired frequency can be switched to a bus bar from one of the switching inputs 24 or 25 by way of an appropriate switch gate 26. Therefore, higher waves are created which are prevented from traversing the low pass filters 27 and 28.
  • the selected frequency fl5,fl6 or f21 passes to the transducers by way of a wide band amplifier 29.
  • An acousto-optical light deflector comprising a crystal employed as a sonic medium, a plurality of piezoelectric transducers carried on said crystal, said piezo-electric transducers comprising crystal plates carried on said crystal sound medium and angularly disposed with respect to one another, each of said transducers having an individual frequency range adjacent to the frequency ranges of the other said transducers and energizable with ultrasonic energy to produce sonic wave fronts in said crystal as a function of the energizing frequency for deflecting a light beam incident approximately parallel with said sonic wave fronts, and control apparatus for supplying said piezo-electric transducers with a controllable variable frequency.
  • An acousto-optical light deflector according to claim 1, wherein said piezo-electric transducers are constructed from different crystal materials so that the sonic amplitudes radiated by the transducers are aligned with each other.
  • control apparatus includes a fixed frequency oscillator, a variable frequency oscillator and a mixer connected between said oscillators and said transducers for superposing said fixed and variable frequencies to provide a control frequency.
  • control apparatus includes a plurality of fixed frequency oscillators each having a different frequency, a bus bar connected to said transducers, and a plurality of electronic switches connected between said oscillators and said bus bar for selectively connecting said oscillators to said transducers.
  • An acousto optical light deflector wherein the total frequency range is divided into octaves and said bus bar is provided as a plurality of buses each associated with a separate octave, and a plurality of low pass filters each interposed between a separate bus and said transducers.

Landscapes

  • Physics & Mathematics (AREA)
  • Nonlinear Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • General Physics & Mathematics (AREA)
  • Optics & Photonics (AREA)
  • Optical Modulation, Optical Deflection, Nonlinear Optics, Optical Demodulation, Optical Logic Elements (AREA)
  • Mechanical Light Control Or Optical Switches (AREA)
US00201652A 1970-12-15 1971-11-24 Acousto-optical light deflector having increased band width and short access time Expired - Lifetime US3759603A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE2061694A DE2061694C3 (de) 1970-12-15 1970-12-15 Akustooptischer Lichtablenker mit erhöhter Bandbreite

Publications (1)

Publication Number Publication Date
US3759603A true US3759603A (en) 1973-09-18

Family

ID=5791040

Family Applications (1)

Application Number Title Priority Date Filing Date
US00201652A Expired - Lifetime US3759603A (en) 1970-12-15 1971-11-24 Acousto-optical light deflector having increased band width and short access time

Country Status (9)

Country Link
US (1) US3759603A (2)
JP (1) JPS5712127B1 (2)
BE (1) BE776729A (2)
DE (1) DE2061694C3 (2)
FR (1) FR2118071B1 (2)
GB (1) GB1380408A (2)
IT (1) IT943817B (2)
LU (1) LU64449A1 (2)
NL (1) NL7117129A (2)

Cited By (18)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2755575A1 (de) * 1976-12-15 1978-06-22 Mta Szamitastech Autom Kutato Einrichtung zur laseraufzeichnung von daten und zeichen
JPS54150153A (en) * 1978-05-17 1979-11-26 Ricoh Co Ltd Multifrequency driving acousto-optic element
US4206347A (en) * 1978-01-12 1980-06-03 Jersey Nuclear-Avco Isotopes, Inc. Acousto-optic multiplexing and demultiplexing
US4250474A (en) * 1979-09-26 1981-02-10 Hughes Aircraft Company Continuous beam steering acoustic wave transducer
US4321564A (en) * 1980-06-18 1982-03-23 Litton Systems, Inc. Sequential beam switching of acousto-optic modulator
US4360272A (en) * 1980-03-20 1982-11-23 Optelecom, Inc. Fiber optic energy sensor and optical demodulation system and methods of making same
US4540245A (en) * 1983-11-10 1985-09-10 Isomet Corporation Apparatus and method for acousto-optic character generation
EP0075700A3 (de) * 1981-09-29 1985-10-16 Siemens Aktiengesellschaft Akustooptischer Lichtablenker mit hoher Auflösung
US4592621A (en) * 1982-07-27 1986-06-03 Hoya Corporation Acoustooptic modulation element and system for acoustooptically carrying out modulation of a plurality of parallel beams by the use of a single acoustooptic medium
US4645309A (en) * 1985-05-01 1987-02-24 Isomet Corporation Method and apparatus for acousto-optic character generation
JPS62205316A (ja) * 1986-02-28 1987-09-09 ローズマウント・アナリティカル・インコーポレイテッド 音響光学的チユ−ナブル・フイルタ及びその同調レンヂを拡大する方法
US4705362A (en) * 1984-10-05 1987-11-10 Westinghouse Electric Corp. Acousto-optic tunable filter with two acoustic channels
US4886346A (en) * 1988-02-16 1989-12-12 Westinghouse Electric Corp. Method and apparatus for improving the angular aperture of an aodlf
US4896949A (en) * 1988-04-27 1990-01-30 Westinghouse Electric Corp. Acousto-optic tunable bandpass filter with strong sideband suppression
US20080247030A1 (en) * 2007-04-06 2008-10-09 Harris Corporation Low cost system and method that implements acousto-optic (ao) rf signal excitation
US20080247027A1 (en) * 2007-04-06 2008-10-09 Harris Corporation Rf phase modulation technique for performing acousto-optic intensity modulation of an optical wavefront
WO2012028610A1 (en) * 2010-08-30 2012-03-08 Micronic Mydata AB Acousto-optic deflectors over one octave
US11984695B1 (en) * 2023-04-07 2024-05-14 Khanh Le Laser transducer

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
HU180848B (en) * 1979-04-18 1983-04-29 Mta Szamitastech Autom Kutato Multiple acoustooptical,multiray intensity modulator and ray deflector
GB2249845A (en) * 1990-11-09 1992-05-20 Marconi Gec Ltd Acousto-optic device

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2754238A (en) * 1951-05-22 1956-07-10 David L Arenberg Method of bonding and article thereby formed
US3055258A (en) * 1951-08-22 1962-09-25 Hurvitz Hyman Bragg diffraction ultrasonic devices
US3614204A (en) * 1969-03-07 1971-10-19 Bell Telephone Labor Inc Acoustic light deflection cells
US3618048A (en) * 1968-07-25 1971-11-02 Gen Electric Random access large-capacity memories
US3653067A (en) * 1970-12-16 1972-03-28 Bell Telephone Labor Inc High-speed printing apparatus

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2754238A (en) * 1951-05-22 1956-07-10 David L Arenberg Method of bonding and article thereby formed
US3055258A (en) * 1951-08-22 1962-09-25 Hurvitz Hyman Bragg diffraction ultrasonic devices
US3618048A (en) * 1968-07-25 1971-11-02 Gen Electric Random access large-capacity memories
US3614204A (en) * 1969-03-07 1971-10-19 Bell Telephone Labor Inc Acoustic light deflection cells
US3653067A (en) * 1970-12-16 1972-03-28 Bell Telephone Labor Inc High-speed printing apparatus

Cited By (27)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2755575A1 (de) * 1976-12-15 1978-06-22 Mta Szamitastech Autom Kutato Einrichtung zur laseraufzeichnung von daten und zeichen
US4206347A (en) * 1978-01-12 1980-06-03 Jersey Nuclear-Avco Isotopes, Inc. Acousto-optic multiplexing and demultiplexing
JPS54150153A (en) * 1978-05-17 1979-11-26 Ricoh Co Ltd Multifrequency driving acousto-optic element
US4250474A (en) * 1979-09-26 1981-02-10 Hughes Aircraft Company Continuous beam steering acoustic wave transducer
US4360272A (en) * 1980-03-20 1982-11-23 Optelecom, Inc. Fiber optic energy sensor and optical demodulation system and methods of making same
US4321564A (en) * 1980-06-18 1982-03-23 Litton Systems, Inc. Sequential beam switching of acousto-optic modulator
EP0075700A3 (de) * 1981-09-29 1985-10-16 Siemens Aktiengesellschaft Akustooptischer Lichtablenker mit hoher Auflösung
US4592621A (en) * 1982-07-27 1986-06-03 Hoya Corporation Acoustooptic modulation element and system for acoustooptically carrying out modulation of a plurality of parallel beams by the use of a single acoustooptic medium
US4540245A (en) * 1983-11-10 1985-09-10 Isomet Corporation Apparatus and method for acousto-optic character generation
US4705362A (en) * 1984-10-05 1987-11-10 Westinghouse Electric Corp. Acousto-optic tunable filter with two acoustic channels
US4645309A (en) * 1985-05-01 1987-02-24 Isomet Corporation Method and apparatus for acousto-optic character generation
JPS62205316A (ja) * 1986-02-28 1987-09-09 ローズマウント・アナリティカル・インコーポレイテッド 音響光学的チユ−ナブル・フイルタ及びその同調レンヂを拡大する方法
US4886346A (en) * 1988-02-16 1989-12-12 Westinghouse Electric Corp. Method and apparatus for improving the angular aperture of an aodlf
US4896949A (en) * 1988-04-27 1990-01-30 Westinghouse Electric Corp. Acousto-optic tunable bandpass filter with strong sideband suppression
US20080247030A1 (en) * 2007-04-06 2008-10-09 Harris Corporation Low cost system and method that implements acousto-optic (ao) rf signal excitation
US20080247027A1 (en) * 2007-04-06 2008-10-09 Harris Corporation Rf phase modulation technique for performing acousto-optic intensity modulation of an optical wavefront
WO2009009174A3 (en) * 2007-04-06 2009-03-19 Harris Corp Acousto-optic modulator and rf phase modulation technique for performing acousto-optic intensity modulation of an optical wavefront
US7538929B2 (en) 2007-04-06 2009-05-26 Harris Corporation RF phase modulation technique for performing acousto-optic intensity modulation of an optical wavefront
US7667888B2 (en) 2007-04-06 2010-02-23 Harris Corporation Low cost system and method that implements acousto-optic (AO) RF signal excitation
WO2012028610A1 (en) * 2010-08-30 2012-03-08 Micronic Mydata AB Acousto-optic deflectors over one octave
CN103080827A (zh) * 2010-08-30 2013-05-01 麦克罗尼克迈达塔有限责任公司 多于一个倍频程的声光偏转器
US8891157B2 (en) 2010-08-30 2014-11-18 Micronic Ab Acousto-optic deflectors over one octave
CN103080827B (zh) * 2010-08-30 2016-04-13 麦克罗尼克迈达塔有限责任公司 多于一个倍频程的声光偏转器
US11984695B1 (en) * 2023-04-07 2024-05-14 Khanh Le Laser transducer
US11999009B1 (en) * 2023-04-07 2024-06-04 IntraAction Corp. Laser system to drill, cut, or modify an electronic circuit
US20240339804A1 (en) * 2023-04-07 2024-10-10 Khanh Le Laser metal deposition systems and methods
US12300961B2 (en) * 2023-04-07 2025-05-13 IntraAction Corp. Laser metal deposition systems and methods

Also Published As

Publication number Publication date
GB1380408A (en) 1975-01-15
LU64449A1 (2) 1972-06-20
JPS5712127B1 (2) 1982-03-09
IT943817B (it) 1973-04-10
BE776729A (fr) 1972-04-04
DE2061694B2 (de) 1973-02-22
DE2061694C3 (de) 1973-09-13
NL7117129A (2) 1972-06-19
DE2061694A1 (de) 1972-07-06
FR2118071B1 (2) 1978-01-13
FR2118071A1 (2) 1972-07-28

Similar Documents

Publication Publication Date Title
US3759603A (en) Acousto-optical light deflector having increased band width and short access time
US4346965A (en) Light modulator/deflector using acoustic surface waves
CA1156750A (en) Acousto-optic device utilizing fresnel zone plate electrode array
US4371964A (en) Circuit arrangement for controlling a multi-beam acousto-optical cell in which Bragg diffraction is used for the generation of a plurality of outgoing laser beams
US5576880A (en) Acousto-optic bragg cell
US3944335A (en) Acousto-optic filter
Slobodnik Jr Nonlinear Effects in Microwave Acoustic LiNbO 3 Surface‐Wave Delay Lines
US3531184A (en) Monochromatic light beam deflection apparatus having two trains of frequency scanned acoustic waves for effecting bragg diffraction
US3633995A (en) Acousto-optic light deflection system
US4381887A (en) Simplified acousto-optic deflector using electronic delays
US3655265A (en) Resonant piezoelectric acousto-optic light filter and apparatus using same
US3609009A (en) Binary light beam deflector using acoustic waves
US3419322A (en) Ultrasonic transducer matching for bragg reflection scanning
Nguyen et al. Efficient wideband guided-wave acoustooptic Bragg diffraction using phased surface acoustic wave array in LiNbO3 waveguides
US3502879A (en) Light scanning device
US4370030A (en) Extended resolution light deflector using surface acoustic waves
US3869197A (en) Light-deflecting system for effecting bragg diffraction over a wide bandwidth
Lee et al. Wide-band guided wave acoustooptic Bragg deflector using a tilted-finger chirp transducer
US3516729A (en) Cylindrical lens compensation of wideaperture bragg diffraction scanning cell
US2509545A (en) Television system for simultaneously modulating and projecting a plurality of light lines
GB2244343A (en) Acousto-optical deflector
US3507553A (en) Ultrasonic digital light deflector
US3614204A (en) Acoustic light deflection cells
US3529886A (en) Iodic acid acousto-optic devices
US3736044A (en) Dispersive acoustical deflector for electromagnetic waves