JPS62914A - Acoustooptic modulating device - Google Patents

Abstract

PURPOSE:To eliminate the need for a lead wire and to suppress a rise in temperature by pressing a conductive elastic body against a transducer by a presser body where a conductive member is arranged. CONSTITUTION:An LiNbO3 plate 2 which have electrodes 3 and 4 is arranged on an acoustooptic medium 1 made of glass to constitute an acoustooptic modulating element 6, which is put in an Al case 12 which has a slanting surface corresponding to the slanting surface of glass 1; and four spacers 13 are implanted and a resin plates 14 and a wiring board 15 are fitted to upper ends with screws. The length of the spacers is so selected that the gap between the reverse surface of the resin plate 14 and the top surface of the glass 1 is 0.5mm. The resin plate 14 have rectangular and circular holes 141 and 142 where an Au electrode and an In vapor-deposited electrode 4 overlap with each other and conductive elastic bodies 17 and 18 formed of Si while Ag plating glass is used as a filler are inserted into those holes, connected to the electrodes 3 and 4 and Cu patterns 151 and 152 on the reverse of the wiring board 15, and led out to Cu patterns 155 and 156 on the top surface through through-holes 153 and 154. In this constitution, the assembly time is shortened remarkably and the radiation effect is also improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to an acousto-optic modulator that modulates light using elastic vibrations of an acousto-optic medium.

[Conventional technology]

FIG. 13 shows an example of this type of acousto-optic modulator that has been conventionally used. In the figure, reference numeral 1 denotes an acousto-optic medium having a substantially rectangular parallelepiped shape, in which a transducer 5 consisting of a top surface KVi piezoelectric plate 2, an upper St pole 3 and a lower electrode 4 arranged on the upper and lower surfaces thereof is arranged. An element 6 is formed. The example shown is a case of 10 channels, and the piezoelectric plate 2 and the lower TFF 14 are used in common, but by providing 10 each upper electrode 3, there are 10 transducers, and each transducer has an upper electrode and Lead wires 7 are attached to the lower part xi and connected to corresponding conductors 9 on a printed wiring board (matching board) 8 on which a matching circuit for impedance matching is mounted.

Note that the matching board 8 is supported and fixed above the transducer 5 at a constant interval by support means (not shown). Further, 10 is a case for supporting the acousto-optic medium 1.

[Problem that the invention seeks to solve]

In this way, in the conventional acousto-optic modulator, the lead wires l were used to connect the upper electrode 3 and lower electrode 4 of the acousto-optic element 6 to the matching substrate 8, which caused the following problems. .

First, when bonding the lead wire T, the upper electrode 3 and the lower electrode 4 with a conductive adhesive, heat treatment at 60° C. for 1.5 hours is required to harden the conductive adhesive. In addition, rapid temperature rises and falls can lead to damage to the piezoelectric plate 2, so heat treatment must be performed with an extremely gentle temperature gradient.
A long processing time of 12 hours was required, which not only resulted in poor productivity but also led to a decrease in the reliability of the acousto-optic device. In addition, the conductive adhesive tends to contaminate the laser beam exit surface of the acousto-optic medium 1, and furthermore, since organic solvents such as thinner are used to dilute the conductive adhesive, there are health problems for workers. Ta.

(9) The matching board 8 is placed above the transducer 5, and the connection between the two using the lead wire r is made in the vertical direction, and the arrangement of the connection points is also complicated, so automation of automatic soldering equipment, etc. It is difficult to introduce the equipment. For this reason, the work is done manually, but since the diameter of the lead wire γ is as small as 0.1B, K 1,1
- It is difficult to create the desired shape of the electrode 1117 and to position the adhesive, and as mentioned above, the width of the upper electrode 30 and the spacing between them are narrow, and care must be taken when applying the conductive adhesive, so the work requires skill. , and required a long time.

This tendency was particularly noticeable in the case of a device having many channels as in the illustrated example, since two lead wires r are required for each channel.

Furthermore, since the IJ-wire γ is thin and the heat dissipation effect is low,
Approximately half of the high frequency power applied to the transducer 5 during operation is converted into heat, raising the temperature of the acousto-optic medium 1, and if the input high frequency power is increased, the acousto-optic medium 1 may be damaged.

[Means for solving problems]

In order to solve these problems, the present invention uses a conductive elastic body in place of the conventional lead wire, and presses the elastic body with a conductive member arranged in correspondence with the elastic body. It is pressed and fixed to the transducer.

As the elastic body, for example, conductive rubber or a thin film of conductive rubber and insulating rubber which are alternately laminated and cut into required dimensions can be used. Further, it may be made of conductive fibers or made of an elastic material such as insulating rubber with thin metal wires embedded therein. Further, such an elastic body is inserted and held in a through hole of a plate member having through holes formed corresponding to the upper and lower electrodes of the transducer.

[Effect]

The electrodes of the transducer are connected to the circuit on the matching board via the conductive elastic body and the conductive member on the pressing body.

〔Example〕

Fig. 1 is an exploded perspective view showing one embodiment of the present invention, Fig. 2 is a perspective view showing an assembled state, Fig. 3 is a front view thereof, and Fig. 4 is an exploded perspective view showing an embodiment of the present invention.
The figure is a cross-sectional view of ff-IT. In the figure, 1 is an acousto-optic medium made of tellurite glass (AOT-44B manufactured by HOYA Co., Ltd.), and on its surface there is a piezoelectric plate 2 made of a 36°Y plate of LiNbO3, an upper electrode 3, and a lower electrode 4. A transducer 5 is arranged to constitute an acousto-optic modulation element 6. Gold is used for the upper electrode 3, and the lower chamber fi14
An indium vapor-deposited film is used as an adhesive between the acousto-optic medium 1 and the piezoelectric plate 2. This is a configuration example in the case of this embodiment F'i 10 channels, and the piezoelectric plate 2 and the lower tff
14 is equivalent to 10 commonly used transducers (5, to 51 degrees) lined up, and an upper electrode 3 (3I to 3...) is formed for each transducer. Assuming that an argon laser with a wavelength of 488 fl and a beam diameter of approximately 0.8 wg is used as the laser beam, each of the upper electrodes 31 to 3. . The dimensions are width 1. On,
Length 14.5mm, distance between 7 centers 1.5
It's a mess. The piezoelectric plate 2i11 is a flat plate with dimensions of 17 mm in length and width and approximately 0.15 mm in thickness, and is placed at the center of the acousto-optic medium 1. The dimensions of the transducer installation surface of this acousto-optic medium 1 are 20+m x 20 inches. A predetermined high frequency power (i'i 80 MHz in this example) is applied between the upper and lower electrodes of each transducer to excite the acousto-optic medium 1.
When an ultrasonic signal is propagated to , laser beams 11. and 11. are incident parallel to each other as shown in FIG. ~11. . is the zero-order light 113. which travels straight through the acousto-optic body 1 making a Bragg angle with respect to the wavefront of the ultrasonic wave. ~11! . and the first-order diffracted light 11, . . . ~11. which is diffracted by the wavefront. . It emits light. At this time, in order to prevent the adverse effects of ultrasonic reflection, the surface of the acousto-optic medium 1 facing the transducer installation surface is cut at an angle of θ-5° with respect to the transducer installation surface, as shown in FIG. The height of the acousto-optic medium 1 is hl#9 inches at the highest point.

The above configuration is the same as the conventional one shown in FIG.

In FIG. 1, reference numeral 12 denotes a case having an inclined surface corresponding to one inclined surface of the acousto-optic medium 1, and is made of aluminum which has good ultrasonic absorption properties. This configuration is basically the same as the case 10 shown in FIG. 13, but in this embodiment, screw holes 121 (121+ to 1214) are provided, and four spacers 13 (13° to 134) are screwed into them. However, screw hole 1214 and spacer 13. is the first
(not shown in the figure), further stack the connector frame 14 and the terminal board 15 made of glass epoxy on its upper end, and fix it with screws 16 (16, ~ 16.) (the nine-head screws 164 are not shown) K. are doing. At this time, the lower surface of the connector frame 14 and the acousto-optic medium 1
The length of one spacer 13 is set so that the distance from the transducer installation surface is 0.5 fl.

The connector frame 14 is made of polyacetal resin and has a flat plate shape with a thickness of 2n, and is connected to the upper electrode 3 of each transducer. ~
It has an approximately rectangular connector insertion hole 141 (141, to 141..) in a portion overlapping with 316, and a circular connector insertion hole 142 in a portion overlapping with lower electrode 4.
(142, to 142..), and each connector insertion hole 141. ~141,6 has length 5 silk, width α51m5
Rectangular parallelepiped elastic connector 1γ (1
γI~17. . ), but also the connector insertion hole 142+
~1421o is a cylindrical elastic connector 18 (18,~18
,. ) (however, 18. does not appear) is inserted.

Each elastane ink connector 1γ and 18 is an elastic body molded from silicone with silver-plated glass as a filler, and is made of a conductive elastomer with low conduction resistance and excellent restoring force (Comerix Elastomer I 13 manufactured by Comerics Inc. in the United States).
50). Each connector insertion hole 141 and 14
The dimensions of connector insertion hole 2 are almost the same as the cross-sectional dimensions of these elastic connectors 11 and 18, but the width of connector insertion hole 141 is 0.45 mm, and the width of connector insertion hole 142 is 0.45 mm.
The diameter of each elastic connector is I Km and 1
7.18 width and diameter,
The elastic connectors 1γ and 18 are prevented from falling out during work.

As mentioned above, the thickness of the collector frame 14 is 2RTX.
, and the transducer installation surface and connector frame 14.
Since the spacing between the bottom surfaces of the elastic connector IT, 18 is approximately α5n, the elastic connector IT, 18 having a height of 31LI is sometimes installed vertically by approximately 0.5cm by the terminal board 15 as shown in FIGS. 7 and 8. *x is compressed, and due to the resulting restoring force, it comes into close contact with the upper electrode 3 and lower electrode 4 of the transducer and the lower surface of the terminal board 15. Note that although FIG. 8 corresponds to the sectional view taken along the line -■ in FIG. 7, the connector frame 14 and the terminal board 15 are omitted in FIG.

Elastic connector 1 on the bottom of the terminal board 15
The contact portion Kl-t with γ, 18, as shown in FIG.
, 152 (152+ to 152+a) are formed.

These copper foil patterns further have through holes 153 (
153, ~153. . ), 154 (154+~1
54.0) on the upper surface as shown in FIG.
1561 to 156+o). Although not shown in the figure, the copper foil patterns 155 and 156 can be easily connected to the circuit formed on the matching board 8 by soldering or the like using a cable or a connector.

Here, as is clear from Figure 7 or Figure 10, 1
Upper electrodes 3I-3 of 0 transformers. . Elastic connector to connect with 17. ~H, o are divided into two rows of 5 pieces each, and the ends of the elastic connectors on one row are arranged approximately as shown in Fig. 7 so that the elastic connectors of the other row do not fit between adjacent elastic connectors. They are arranged alternately so that they are located on a straight line as shown by the broken line. For each elastic connector 1γ, the longer the length tl, the larger the cross-sectional area, lowering the conduction resistance and reducing the power loss.On the other hand, when the adjacent connectors overlap in parallel, the crosstalk increases. This will reduce the performance of the device. For example, in this example, 1
In the example of channel 0, when the n-th channel is selected and a high-frequency signal is applied only to that transducer 5n, calculate the amount of diffracted light obtained on the n-th channel. What is the amount of diffracted light obtained in the n-th channel when a high-frequency signal is applied to these transducers? , the crosstalk is expressed as 10 lot i (dB), and in this example, the worst value was -19.7 dB.

In contrast, the length of each elastic connector 1T is 1
0. , when 10 sheets were arranged in parallel in one row, the crosstalk was t'1-16.2 dB, which was 3.5 dB worse. Therefore, the configuration shown in the figure was adopted to suppress the conduction resistance to a low level without increasing the crosstalk, but if there is no need to take into account losstalk, as shown in Figure 11. to 1
The length K of the upper electrode is approximately equal to the connector insertion hole 14
1' and elastic connector 1γ may be used.

In addition, in the above-mentioned embodiment, Comeric elastomer Nct13, which has low conduction resistance and excellent restoring force, was used as described above.
50 was used as an elastic connector, but the present invention is not limited to this; for example, the w series elastic connector manufactured by Toshiku Co., Ltd. is a type in which a large number of thin gold wires are embedded in silicone rubber. It is also possible to use molded metal mesh such as Shield Lie/1 manufactured by Taiyo Kinami Co., Ltd.

Further, as shown in FIG. 12, a laminated type elastic connector 11'' in which conductive rubber thin films 17A and insulating rubber thin films 1γB are alternately laminated may be used. In this case, as shown in the figure, Connector insertion hole 141 corresponding to
``ii.One piece is sufficient.The example shown is a laminated type elastic connector corresponding to the upper part of the transducer, but it is also possible to adopt a similar configuration for the elastic connector corresponding to the lower electrode. be.

In addition, in case 3, the water bottle 19 shown by the broken line in Fig. 1 is added.
A connector frame 14 and a terminal board 1 are provided.
Through hole 20 corresponding to 5. : l are provided, and these through holes 20
, 21, it becomes easy to accurately position the upper and lower electrodes of the transducer and the elastane ink connector.

Although the case of 10 channels has been described above, the present invention is not limited to this, and can be similarly applied to the case of arbitrary channels.

〔Effect of the invention〕

As explained above, according to the present invention, a conductive elastic body inserted and held in a through hole of an elastic body holding plate is used instead of a conventional lead wire, and a conductive member is arranged corresponding to the elastic body. By pressing and fixing with a plate, there is no need for heat treatment to harden the conductive adhesive, and the operator does not need to be skilled, so the working time can be significantly shortened. For example, a process that used to take about 13 hours now takes about 10 minutes at most. In addition, there is no reduction in reliability due to thermal stress caused by heat treatment, and problems of contamination of the acousto-optic medium and hygiene of workers can be solved at the same time.

Furthermore, compared to the conventional connection method using lead wires, the contact area between the conductive elastic body and the transducer can be increased, which improves the heat dissipation effect and suppresses temperature rise. For example, applying a high frequency signal of 1.7 watts to the conventional example shown in Fig. 13 and the embodiment shown in Fig. @1,
When the temperature rise of the acousto-optic medium 1 was measured using Thermal Pure (Nippon Avionics Co., Ltd. ff) K, it was confirmed that the temperature of the latter was 2-5°C lower on average than the former. This means that the present invention provides a highly reliable device that can withstand higher frequency applications than conventional devices. Note that this heat dissipation effect can be further enhanced by using an insulating material with high thermal conductivity, such as Denkaboro/Nitride (manufactured by Keikagaku Kogyo Co., Ltd.), for the elastic body holding plate.

[Brief explanation of the drawing]

1 to 10 show an embodiment of the present invention, and a first embodiment of the present invention is shown in FIG.
The figure is an exploded perspective view, Fig. 2 is a perspective view, Fig. 3 is a front view, Fig. 4 is an IV-IM sectional view, Fig. 5 is a perspective view showing the state of laser light modulation, and Fig. 6 is an acousto-optic A side view of the medium, FIG. 7 is a plan view showing details of the contact between the elastic connector and the transducer, FIG. A top view and a bottom view, FIGS. 11 and 12 are exploded perspective views showing other embodiments of the present invention, and FIG. 13 is a perspective view showing a conventional example. 1... Acousto-optic medium, 2... Piezoelectric plate, 3 (31
~3. . )... Upper electrode, 4... Lower ix pole, s
... war transducer, 6... acousto-optic transducer X4
X child, 12... Case (support body), 13 (13, ~
13. )... Spacer (positioning means), 14...
・φ connector frame (elastic body holding plate), 15...
Terminal board (pressing body), 1r (1γ, ~1γ+o
), 18 (18+~18..)... Elastic connector (elastic body with conductivity:), 141 (
141, ~141. . ), 141', 141'. 142 (142, ~142..)... Connector insertion hole, 151 (151, ~151..), 152
(152,~1521°)・-0, Steel foil pattern. Representative of Hoya Co., Ltd. Masaki Yamakawa (and 2 others) Figure 5 Figure 7 Figure 8 Figure 9 Figure 10 Figure 13

Claims (1)

[Scope of Claims] An acousto-optic modulation element having an acousto-optic medium and a transducer comprising an upper electrode and a lower electrode respectively arranged on the upper and lower surfaces of a piezoelectric plate provided on one principal surface of the acousto-optic medium; a support body for supporting the acousto-optic modulation element; an elastic body holding plate having a through hole provided corresponding to the upper electrode and the lower electrode and having a conductive elastic body inserted into the through hole; a pressing body having a conductive member arranged thereon corresponding to the elastic body on a surface facing the body holding plate; and positioning means for fixing the distance between the supporting body and the elastic body holding plate; an acousto-optic modulator, which is pressed and fixed onto the transducer.