JP3807227B2 - Acoustooptic device and manufacturing method thereof - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an acoustooptic device that generates and uses light diffraction and a method for manufacturing the same.
[0002]
[Prior art]
Conventionally, as an acoustooptic device, for example, as shown in FIG. 11, tellurite glass or lead molybdate single crystal (PbMoO _Four ), Etc., an ultrasonic transducer 32 made of a piezoelectric element (transducer) is metal-bonded in a vacuum using tin.
[0003]
In such an acoustooptic device, when an ultrasonic wave is generated in the acoustooptic medium 31 by the ultrasonic transducer 32 along the longitudinal direction, the refractive index change periodically generated in the acoustooptic medium 31 by the photoelastic effect. However, since it becomes a pseudo diffraction grating of light, the light 33 incident on the acoustooptic medium 31 undergoes diffraction and changes its direction.
[0004]
[Problems to be solved by the invention]
However, in the conventional acoustooptic device, the ultrasonic transducer 32 is metal-bonded to the longitudinal end surface of the acoustooptic medium 31 using tin in vacuum, which increases the number of manufacturing steps and increases costs. The problem of being invited has arisen.
[0005]
Further, in the conventional acousto-optic device, since metal bonding in a vacuum is difficult, there is a problem that the bonding strength is lowered with time and defective bonding occurs, resulting in poor durability.
[0006]
[Means for Solving the Problems]
In order to solve the above problems, the acoustooptic device of the present invention is provided with an acoustooptic medium part made of translucent ceramics, and an ultrasonic transducer part made of piezoelectric ceramics is connected to the acoustooptic medium part. The internal electrodes for generating ultrasonic waves are provided in the ultrasonic transducer unit by exposing one end of the internal electrodes to the outside and alternately arranging the exposed portions. A pair of external electrodes for supplying electric power is provided, and the acousto-optic medium part and the ultrasonic transducer part are integrally formed by firing.
[0007]
According to the above configuration, the internal electrodes are arranged so that one end of the internal electrodes are exposed to the outside and the exposed portions are alternately arranged. It is possible to generate ultrasonic waves from the transducer unit and propagate the ultrasonic waves to the acousto-optic medium unit connected to the ultrasonic transducer unit.
[0008]
Therefore, a pseudo diffraction grating is formed in accordance with the change of the refractive index in the acousto-optic medium portion whose refractive index is changed by the propagated ultrasonic wave. As a result, when light is incident on the acousto-optic medium portion with an inclination relative to the propagation direction of the ultrasonic wave, diffraction can be generated for the light.
[0009]
In addition, in the above configuration, the acoustooptic medium part and the ultrasonic vibrator part are integrally formed by firing by providing the acoustooptic medium part from translucent ceramics and the ultrasonic vibrator part from piezoelectric ceramics. Therefore, it is possible to reduce the time and labor required for connecting the acousto-optic medium part and the ultrasonic transducer part, and to increase the connection strength. As a result, with the above configuration, the cost can be reduced and the durability can be improved.
[0010]
In the acoustooptic device, the translucent ceramic contains at least one of Ba, Sr, and Ca at the A site, and Zr, Hf, Ta, Zn, Nb, Sb, Mg, Ti, and Al at the B site. A general formula ABO containing one or more rare earths _Three It is preferable to have a perovskite crystal structure represented by: According to the said structure, since it can be set as the translucent ceramics excellent in translucency, it can exhibit the outstanding optical characteristic.
[0011]
In order to solve the above-described problem, another acousto-optic device of the present invention has an internal electrode for generating ultrasonic waves on a part of a substrate made of translucent piezoelectric ceramics, one end of which is externally exposed. It is characterized in that a pair of external electrodes are provided so as to be exposed and arranged so that the exposed portions are alternately arranged to supply electric power to each internal electrode.
[0012]
In the acoustooptic device, the piezoelectric ceramic is PLZT [(Pb, La) (Zr, Ti) O. _Three ], Preferably at least one selected from the group consisting of lithium tantalate and lithium niobate.
[0013]
According to the above configuration, since the base material is made of translucent piezoelectric ceramics, a part of the base material on which the internal electrode is formed functions as an ultrasonic transducer part, and the other part is an acoustooptic medium part. can do.
[0014]
Further, in the above configuration, the internal electrode is arranged so that one end of the internal electrode is exposed to the outside and the exposed portion is alternated.By supplying power from the external electrode to each internal electrode, It is possible to generate an ultrasonic wave from the ultrasonic transducer part serving as a base material between the internal electrodes and propagate it to the acousto-optic medium unit integrated with the ultrasonic vibrator unit.
[0015]
Therefore, a pseudo diffraction grating is formed in accordance with the change of the refractive index in the acousto-optic medium portion whose refractive index is changed by the propagated ultrasonic wave. As a result, when light is incident on the acousto-optic medium portion with an inclination relative to the propagation direction of the ultrasonic wave, diffraction can be generated for the light.
[0016]
In addition, in the above configuration, the acousto-optic medium part and the ultrasonic vibrator part can be integrally provided simultaneously from piezoelectric ceramics, and the acousto-optic medium part and the ultrasonic vibrator part are integrally formed by firing. Since they can be connected to each other, it is possible to reduce the time and effort of connecting the acousto-optic medium part and the ultrasonic transducer part, and to increase the connection strength. As a result, with the above configuration, the cost can be reduced and the durability can be improved.
[0017]
In order to solve the above-described problems, a method for producing an acoustooptic device according to the present invention produces a sheet-like first green sheet from a raw material powder of translucent ceramics, A second green sheet is produced, an internal electrode is formed on the surface of the second green sheet, and the second green sheet is mutually exposed such that one end of the internal electrode is exposed to the outside and the exposed portions are alternated. The acousto-optic medium part which consists of each 1st raw sheet | seat by laminating | stacking and laminating | stacking the said 1st green sheet following the lamination | stacking, producing a composite laminated body, and baking and integrating the said composite laminated body And an ultrasonic transducer part made up of each second raw sheet.
[0018]
In order to solve the above-described problem, another acousto-optic device manufacturing method according to the present invention produces a sheet-like third green sheet from a raw material powder of translucent piezoelectric ceramics. An internal electrode is formed on the surface of the portion, and the third raw sheet is laminated and baked to form an ultrasonic transducer portion that is a formation portion of the internal electrode, and an acoustooptic medium portion other than the formation portion, and Is formed integrally.
[0019]
According to the above method, by laminating, each internal electrode formed inside the ultrasonic transducer part can be easily and reliably produced. For this reason, in the above method, an acoustooptic device in which the acoustooptic medium portion and the ultrasonic transducer portion are integrated can be obtained stably.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
Each embodiment of the present invention will be described with reference to FIGS. 1 to 10 as follows.
[0021]
[First embodiment]
In the acoustooptic device according to the first embodiment of the present invention, as shown in FIG. 1, the acoustooptic medium portion 1 made of translucent ceramics is provided in a substantially rectangular parallelepiped shape, for example, a quadrangular prism shape, and made of piezoelectric ceramics. The ultrasonic transducer section 2 has a substantially rectangular parallelepiped shape having the same cross-sectional area as that of the acoustooptic medium section 1, for example, a quadrangular prism shape, and is coaxial with the longitudinal end face of the acoustooptic medium section 1. They are connected so as to become one.
[0022]
In the acoustooptic device, an internal electrode 3 for generating ultrasonic waves in the ultrasonic transducer section 2 has one end exposed to the outside, and the exposed portions are alternately arranged to be adjacent to each other. Piezoelectric ceramics are tightly sandwiched between the electrodes 3, and a pair of external electrodes 4 for supplying electric power to the internal electrodes 3 are also provided. In addition, although not shown in figure, the edge part in which the internal electrode 3 was formed is an ultrasonic wave which consists of an elastic body etc. in order to prevent reflection of the ultrasonic wave in the edge part on the opposite side to a longitudinal direction. An absorption part may be provided.
[0023]
In the acoustooptic device, the acoustooptic medium portion 1 and the ultrasonic transducer portion 2 are integrally formed by firing. As a result, in the acoustooptic device, the internal electrode 3 is arranged so that one end of the internal electrode 3 is exposed to the outside and the exposed portions are alternately arranged, so that power is supplied from the external electrode 4 to each internal electrode 3. Thus, an ultrasonic wave is generated from the ultrasonic transducer unit 2 and the ultrasonic wave 5 is transmitted to the acousto-optical medium unit 1 connected thereto via the ultrasonic transducer unit 2. 1 can be propagated along the longitudinal direction.
[0024]
Therefore, in the acousto-optic medium unit 1 whose refractive index is changed by the propagated ultrasonic wave 5, a pseudo diffraction grating is formed according to the change in the refractive index. Thereby, when the light 6 is incident on the acoustooptic medium unit 1 with an inclination with respect to the propagation direction of the ultrasonic wave 5, diffraction can be generated with respect to the light 6, for example, primary light or secondary light. Diffracted light 7 such as light can be generated. Such diffracted light 7 can be applied to an optical element such as a bifocal lens.
[0025]
In addition, in the above configuration, the acoustooptic medium unit 1 and the ultrasonic transducer unit 2 are fired by providing the acoustooptic unit 1 from translucent ceramics and the ultrasonic transducer unit 2 from piezoelectric ceramics. Therefore, it is possible to reduce the labor of connecting the acousto-optic medium unit 1 and the ultrasonic transducer unit 2 as compared with the related art, and to increase the connection (bonding) strength. As a result, with the above configuration, the cost can be reduced and the durability can be improved.
[0026]
The translucent ceramic is formed by firing and has a refractive index of 20% or more, more preferably 50% or more, and any refractive index, or birefringence. The refractive index is 1.9 or more, and a paraelectric material (not showing birefringence) is preferable.
[0027]
Next, regarding the method of manufacturing the acoustooptic device, Ba (Mg, Ta) O _Three This will be described based on an example using translucent ceramics having a main perovskite crystal structure as a main crystal phase.
[0028]
First, as a raw material powder for translucent ceramics, high-purity BaCO _Three , SnO ₂ , ZrO ₂ , MgCO _Three And Ta ₂ O _Five Each powder was prepared. Then, each said raw material powder is made into Ba [(Sn _u Zr _1-u ) _x Mg _y Ta _z ] _v O _w In such a composition formula, u = 0.67, x = 0.16, y = 0.29, z = 0.55, v = 1.02. For 16 hours to obtain a mixture. Note that w is approximately 3 after firing. x, y and z satisfy the relationship x + y + z = 1.00.
[0029]
The mixture was dried and calcined at 1300 ° C. for 3 hours to obtain a calcined product. This calcined product was placed in a ball mill together with water and an organic binder, and wet pulverized for 16 hours to obtain a slurry. As an organic binder, it has a function as a binder and reacts with oxygen in the atmosphere at a temperature of, for example, about 500 ° C. in the atmosphere before the sintering temperature is reached during sintering. As long as it disappears, it may be ethyl cellulose.
[0030]
Using this slurry, a sheet was formed by, for example, a doctor blade method to obtain a first green sheet having a thickness of about 20 μm to 100 μm. This first green sheet was cut into a rectangular shape of, for example, 30 mm × 40 mm, and a first green sheet 8 before firing was produced as shown in FIG.
[0031]
On the other hand, a slurry mainly composed of barium titanate-based piezoelectric ceramic material powder is used for the ultrasonic vibrator unit 2 and is formed into a sheet by, for example, a doctor blade method, and the second green having a thickness of about 20 μm to 100 μm. A sheet was obtained.
[0032]
This second green sheet was cut into a rectangular shape having the same dimensions as the first green sheet to produce a second green sheet 9. A platinum paste serving as the internal electrode 3 was screen-printed on the surface of the second green sheet 9 so as to have a thickness of about several μm and dried to form an internal electrode paste portion 9a. The internal electrode paste portion 9a is formed by screen printing so as to be thinner than the second green sheet 9, for example, about several μm thick (preferably 1/5 or less the thickness of the second green sheet 9). And drying.
[0033]
At this time, the internal electrode paste portion 9a reaches the end of the three sides of the second green sheet 9, but the end of the other side is the length of the side of the second green sheet 9. It is formed with an interval of about 1/10. Therefore, in the second green sheet 9, the internal electrode paste portion 9 a to be the internal electrode 3 is formed on the surface of the second green sheet 9 excluding one side portion.
[0034]
Subsequently, each of the plurality of first green sheets 8 and each of the second green sheets 9 were laminated together along their thickness direction and pressed to produce a composite laminate 10. At this time, in the composite laminate 10, each second green sheet 9 is exposed so that one end of the internal electrode paste portion 9 a serving as the internal electrode 3 is exposed to the outside, and the exposed portions are alternated. The non-exposed portions are laminated together so that they appear alternately on the outer surface.
[0035]
Next, this composite laminate 10 was embedded in the same composition powder. The same composition powder is obtained by pulverizing a fired product obtained by firing the same composition system as that of the translucent ceramic, and does not need to have translucency. As the said same composition system, if each component is the same as the said translucent ceramics, those composition ratios may differ, but the substantially same thing is preferable. Therefore, the composite laminate 10 embedded in the same composition powder is disposed close to the same composition system and fired.
[0036]
In the firing furnace, the composite laminate 10 is first heated together with the same composition powder in the atmosphere composition to raise the temperature to remove the organic binder contained in the composite laminate 10 by heating. The temperature is raised to a temperature range where degassing occurs, and after debinding, oxygen is injected into the atmosphere while the temperature is raised to raise the oxygen concentration from the atmospheric oxygen concentration, for example, 95% (volume%), and firing The firing atmosphere in the furnace was adjusted.
[0037]
Thereafter, the firing atmosphere is maintained, the temperature in the firing furnace is increased to a firing temperature of, for example, 1600 ° C., and the composite laminate 10 is fired for 20 hours while maintaining the firing atmosphere and the firing temperature. A sintered body was obtained from the laminate 10. As shown in FIG. 3, external electrodes 4 were formed on the sintered body by baking a silver (Ag) paste so that electric power could be supplied to the internal electrodes 3 exposed on both sides. .
[0038]
In this way, Ba (Mg, Ta) O according to the first embodiment of the present invention. _Three Acoustooptics in which an ultrasonic transducer unit 2 is integrally formed and connected to an acoustooptic medium unit 1 made of translucent ceramics, which is a sintered body having a composite perovskite crystal structure as a main crystal phase. An element is obtained.
[0039]
In such an acoustooptic device, since the ultrasonic wave generated from the ultrasonic transducer unit 2 becomes longitudinal vibration, the electro-mechanical conversion efficiency can be increased and the refractive index is high, so that the size can be reduced. In addition, since they are integrated, the bonding strength between the acoustooptic medium unit 1 and the ultrasonic transducer unit 2 can be improved, and the durability can be improved.
[0040]
As a result of analysis by X-ray diffraction (XRD), the translucent ceramic obtained in this way is Ba (Mg, Ta) O. _Three It was confirmed to have a crystal structure of the system. Here, Ba is restricted to the A site of the composite perovskite crystal structure, and Mg and Ta entering the B site are restricted by their ionic radii and valence.
[0041]
The firing temperature and firing time are set depending on the composition to be used. In the above composition, the firing time may be fired within a range of 1550 ° C. to 1650 ° C. for 10 hours or more. If baked on the said conditions, the translucent ceramics which are a highly transparent sintered body will be obtained. Since the translucent ceramic is a paraelectric polycrystal, it does not exhibit birefringence.
[0042]
Next, the translucent ceramics will be described. First, a disc-shaped sample of translucent ceramics was prepared, and the linear transmittance and refractive index of the sample were measured. The refractive index was 2.1. Further, as shown in FIG. 4, the linear transmittance is 40% or more when the light wavelength is in the range of 300 nm to 900 nm, 60% or more in the range of 350 nm to 900 nm, and 70% or more in the range of 380 nm to 900 nm. Met.
[0043]
The linear transmittance is measured using a spectrophotometer (UV-200S) manufactured by Shimadzu in the range of 180 to 900 nm, and the refractive index is measured using a prism coupler (MODEL 2010, manufactured by Metricon). Was measured at 633 nm.
[0044]
Hereinafter, it will be described that the linear transmittance of the translucent ceramic used is almost a theoretical value. First, at the time of measuring the linear transmittance, light enters from the air perpendicularly to the surface of the sample. For this reason, when the refractive index (n) is 2.1, the total reflectance on the front and back surfaces of the translucent ceramic sample is 23%. Therefore, the theoretical value (theoretical maximum value) of the linear transmittance of the translucent ceramic is 77%.
[0045]
The sample of translucent ceramics had a linear transmittance of approximately 75% at 400 nm or more, indicating a value equivalent to the theoretical value. This indicates that there are almost no defects in the crystal of the translucent ceramics, which confirms that the translucent ceramics can be used as an optical component. Such a translucent ceramic can be made to have a linear transmittance of almost 100% by applying an AR (antireflection film) coating on the surface.
[0046]
Next, the influence of the oxygen concentration of the firing atmosphere on the linear transmittance was examined. First, each translucent ceramic was prepared with various oxygen concentrations in the firing atmosphere. Subsequently, the linear transmittance of each translucent ceramic was examined, and the result is shown in FIG. In this result, the relationship between the oxygen concentration and the linear transmittance shows a positive correlation, and the oxygen concentration in the firing atmosphere is preferably 45% or more (a range in which the linear transmittance is 20% or more), preferably 75% or more ( It was found that the range in which the linear transmittance was 60% or more was more preferable, and 90% or more was more preferable.
[0047]
[Second Embodiment]
The acoustooptic device according to the second embodiment of the present invention will be described below with reference to FIGS. 6 to 8. First, the acoustooptic device is made of translucent piezoelectric ceramics as shown in FIG. The internal electrode 23 for generating an ultrasonic wave is exposed to a part of the substantially rectangular parallelepiped base 21 such as one end in the longitudinal direction of the base 21 so that one end is exposed to the outside and the exposed portions are alternately arranged. A pair of external electrodes 24 for supplying electric power to the respective internal electrodes 23 are provided.
[0048]
Therefore, in the acoustooptic device, since the base material 21 is made of translucent piezoelectric ceramics, the portion of the base material 21 on which the internal electrode 23 is formed has the same function as that of the ultrasonic transducer section 2 described above. The other portion functions as an acoustooptic medium unit 26 having the same function as the acoustooptic medium unit 1 described above.
[0049]
In such an acousto-optic device, the acousto-optic medium unit 26 and the ultrasonic transducer unit 25 are simultaneously and integrally provided from translucent piezoelectric ceramics. Since the child portion 25 can be integrally formed by firing and connected to each other, it is possible to reduce the time and effort of connecting the acousto-optic medium portion 26 and the ultrasonic transducer portion 25 and to increase the connection strength. Become. As a result, the acoustooptic device can be improved in durability and inexpensive.
[0050]
Next, a method for manufacturing such an acousto-optic device will be described. First, as shown in FIG. 7, a slurry mainly composed of a raw material powder of PLZT-based piezoelectric ceramics having translucency is prepared. From the slurry, a sheet was formed by a doctor blade method to obtain a green sheet having a thickness of about 20 μm to 100 μm. This green sheet was cut into a rectangular shape to prepare a third raw sheet 27.
[0051]
Thereafter, the internal electrode paste portion 27a was formed on the surface of the third raw sheet 27 by, for example, printing in the same manner as the internal electrode paste portion 9a described above. The internal electrode paste portion 27a was formed by screen printing a palladium paste to a thickness of about several μm and drying. Subsequently, the third raw sheet 27 in which the internal electrode paste portion 27a is not formed and the formed third raw sheet 27 are laminated in the thickness direction so that the internal electrode 23 is formed. A composite laminate 28 similar to the composite laminate 10 described above was obtained by pressure bonding. Except for firing such a composite laminate 28 at a firing temperature of 1200 ° C. for 6 hours, a sintered body having translucency was obtained in the same manner as the firing method for the composite laminate 10 described above. As shown in FIG. 8, a silver paste was baked on the sintered body in the same manner as described above to form the external electrode 24, thereby obtaining an acoustooptic device according to the second embodiment.
[0052]
In such an acoustooptic device, the acoustooptic medium unit 26 and the ultrasonic transducer unit 25 can be integrated to realize a structure, and the coupling (bonding) strength between the two can be increased. Since the acoustooptic medium part 26 and the ultrasonic transducer part 25 can be prepared from the same material, the acoustooptic element can be easily manufactured.
[0053]
[Third embodiment]
In the above, Ba (Mg, Ta) O is used as the translucent ceramic. _Three Although an example using a system is given, other translucent ceramics may be used, for example, Ba (Zn, Ta) O. _Three It is also possible to use a translucent ceramic. The acoustooptic device according to the third embodiment using this translucent ceramic will be described as follows. First, as a raw material, high-purity BaCO _Three , ZrO ₂ ZnO and Ta ₂ O _Five Prepared.
[0054]
Subsequently, each of these raw materials is replaced with Ba (Zr _x Zn _y Ta _z ) _a O _w In the composition formula, x = 0.03, y = 0.32, z = 0.65, and a = 1.02, respectively, and weighed them together in a ball mill for 16 hours. Mix to obtain a mixture. Note that w is approximately 3 after firing.
[0055]
The mixture was dried and calcined at 1200 ° C. for 3 hours to obtain a calcined product. This calcined product was placed in a ball mill together with water and an organic binder, and wet pulverized for 16 hours to obtain a slurry. Using this slurry, Ba (Mg, Ta) O according to the first embodiment described above, except that the firing temperature was changed to 1500 ° C. and the firing time was changed to 10 hours. _Three An acoustooptic device according to the third embodiment was prepared in the same manner as the system.
[0056]
The firing temperature and firing time are set depending on the composition to be used. In the above composition, the firing temperature may be 1500 ° C. to 1600 ° C. and the firing time may be 5 hours or more. A sintered body with high translucency can be obtained by firing under the above conditions.
[0057]
Similarly, the linear transmittance and the refractive index of this translucent ceramic were measured. The refractive index of the translucent ceramic was 2.1. Moreover, the result of the linear transmittance was shown according to FIG. In the above results, the linear transmittance was 50% or more from 400 nm to 900 nm. As described above, in the above, Ba (Zn, Ta) O _Three An example of a translucent ceramic is shown, and the Ba (Mg, Ta) O described above is shown. _Three It can be seen that even in a material system having a composite perovskite crystal phase different from the system as a main crystal phase, a material having a high linear transmittance and a high refractive index is obtained.
[0058]
[Fourth embodiment]
Next, Ba (Mg, Ta) O having an iron group metal (Fe, Co, Ni) _Three An acoustooptic device according to a fourth embodiment using translucent ceramics having a main perovskite crystal structure as the main crystal phase will be described.
[0059]
First, as a raw material, high-purity BaCO _Three , SnO ₂ , ZrO ₂ , MgCO _Three , NiO and Ta ₂ O _Five Prepared. Subsequently, the above raw materials excluding NiO are replaced with Ba [(Sn _u Zr _1-u ) _x Mg _y Ta _z ] _v O _w In the composition formula, u = 1, x = 0.15, y = 0.29, z = 0.56, v = 1.02, respectively, weighed so as to obtain a composition, and together with a ball mill, 16 The mixture was obtained by wet mixing for a period of time. Note that w is approximately 3 after firing.
[0060]
The mixture was dried and calcined at 1300 ° C. for 3 hours to obtain a calcined product. To this calcined product, NiO was added in an amount of 1.0 mol% as Ni, and this added calcined product was placed in a ball mill together with water and an organic binder, and wet pulverized for 16 hours to obtain a slurry. Using this slurry, the aforementioned Ba (Mg, Ta) O is used. _Three Acousto-optic elements were prepared in the same manner as the system.
[0061]
About the translucent ceramics of this acoustooptic device, the linear transmittance and refractive index were measured, respectively. In addition, as a first comparative example, a first comparative sample prepared in the same manner was also manufactured except that NiO was added so as to be 1.5 mol% as Ni.
[0062]
The refractive index of the translucent ceramic is 2.1, and the wavelength dependence of the linear transmittance is shown in FIG. As apparent from FIG. 9, in the above translucent ceramic, it can be seen that a steep transmission peak appears at λ = 400 nm and 300 nm when a small amount of NiO is added. This wavelength band coincides with a wavelength band such as a blue-violet laser described as a short wavelength laser. Therefore, the acoustooptic device using the translucent ceramics functions as a band transmission filter for these lasers. It can also be used as a combination.
[0063]
The wavelength dependence of the linear transmittance of the first comparative sample is also shown in FIG. As is apparent from FIG. 9, it can be seen that the addition of 1.5 mol% NiO makes the linear transmittance extremely low in the first comparative sample. From this, it can be seen that the amount of NiO added is preferably 1.2 mol% or less, and more preferably 1.0 mol% or less. In the above, Ni is used as an additive, but other iron group metals such as Fe and Co can be used as necessary.
[0064]
[Fifth embodiment]
Furthermore, other Ba (Mg, Ta) O _Three The acousto-optic device according to the fifth embodiment using translucent ceramics having a composite perovskite type crystal structure as the main crystal phase will be described as follows.
[0065]
First, as a raw material, high-purity BaCO _Three , MgCO _Three And Ta ₂ O _Five Prepared. Subsequently, each of the above raw materials is changed to Ba (Mg _y Ta _z ) _v O _w In the composition formula, y = 0.33, z = 0.67, and v = 1.03 were weighed to obtain compositions.
[0066]
Subsequently, Ba (Mg, Ta) O described above _Three An acoustooptic device was produced in the same manner as the acoustooptic device using the system. The linear transmittance of the translucent ceramic was measured, and the result is shown in FIG. As a result, the linear transmittance is about 20%, which is slightly lower than that of the above-described translucent ceramics. However, by applying an antireflection coating, the linear transmittance can be used as a material for the acoustooptic medium unit 1. Is possible.
[0067]
In each of the above examples, the example of each translucent ceramic having a specific composition ratio has been described. However, the translucent ceramic used for the acoustooptic device of the present invention is not limited to these.
[0068]
Furthermore, in each of the above examples, in order to place the composite laminate 10 in the vicinity of the same composition system, an example was given in which the composite laminate 10 was embedded in the same composition powder. For example, a sintered body plate or sheath having the same composition as that of the composite laminate 10 may be used. When the above plate is used, the composite laminate 10 may be placed on the plate and fired. When the above sheath is used, the composite laminate 10 is placed in the sheath. And firing.
[0069]
In the manufacturing method of the present invention, an example in which the composite laminate 10 for an acoustooptic device was individually manufactured was given. However, as shown in FIG. 10, the area is larger than that of the first and second green sheets. First and second large green sheets are prepared, and a plurality of internal electrode paste portions 9a are formed on the second large green sheet.
[0070]
Subsequently, a plurality of the first and second large green sheets are stacked on each other so as to form the internal electrodes 3 from the internal electrode paste portions 9a, respectively, and are laminated in the thickness direction to form a stacked block 11. Each of the composite laminates 10 may be collectively formed by cutting the laminate block 11 along the cutting lines 16 and 17 in the stacking direction and dividing the laminate block 11 into individual composite laminates 10.
[0071]
In addition, in FIG. 10, the example which formed each internal electrode paste part 9a with respect to the composite laminated body 10 was given, but each part of the lamination | stacking block 11 used as each other composite laminated body 10 is also shown, respectively. An internal electrode paste portion 9a is formed. The same applies to the composite laminate 28 described above.
[0072]
【The invention's effect】
As described above, the acoustooptic device of the present invention is provided with an acoustooptic medium portion made of translucent ceramics, and an ultrasonic transducer portion made of piezoelectric ceramics is connected to the acoustooptic medium portion. An internal electrode for generating a sound wave is provided inside the ultrasonic transducer unit with one end exposed to the outside and the exposed portions arranged alternately, and an acousto-optic medium unit and an ultrasonic transducer unit And are integrally formed by firing.
[0073]
Therefore, in the above configuration, the acoustooptic medium part and the ultrasonic vibrator part are integrally formed by firing by providing the acoustooptic medium part from translucent ceramics and the ultrasonic vibrator part from piezoelectric ceramics. Therefore, it is possible to reduce the time and labor required for connecting the acousto-optic medium part and the ultrasonic transducer part, and to increase the connection strength. As a result, the configuration described above is advantageous in that it can be made inexpensive and the durability can be improved.
[0074]
As described above, the other acousto-optic device of the present invention has an internal electrode for generating ultrasonic waves in a part of the base material made of translucent piezoelectric ceramics, with one end exposed to the outside, The exposed portions are alternately arranged, and a pair of external electrodes for supplying electric power to the respective internal electrodes is provided.
[0075]
As described above, the acousto-optic device manufacturing method of the present invention is a sheet comprising a sheet-like first raw sheet and a piezoelectric ceramic raw material powder made of a light-transmitting ceramic raw material powder and having an internal electrode on the surface. From each first green sheet, by baking and integrating a composite laminated body that is laminated with each other so that one end of the internal electrode is exposed to the outside and the exposed portions are alternated The acousto-optic medium part and the ultrasonic transducer part made of each second raw sheet are integrally formed with each other.
[0076]
Therefore, in the above method, by laminating, the internal electrodes are integrated inside, and the acoustooptic medium part and the ultrasonic transducer part are integrally formed with each other. There is an effect that it is possible to stably manufacture an acoustooptic device with reduced cost.
[0077]
As described above, the other method for producing the acoustooptic device of the present invention is to produce a sheet-like third raw sheet from the raw powder of the translucent piezoelectric ceramic, and on the surface of a part of the third raw sheet, An internal electrode is formed, and the third raw sheet is laminated and baked to integrally form an ultrasonic transducer part, which is an internal electrode formation part, and an acousto-optic medium part other than the formation part. It is a method to do.
[0078]
According to the above method, by laminating, each internal electrode formed inside the ultrasonic transducer part can be easily and reliably produced. For this reason, the above-described method has an effect that the acoustooptic element having excellent durability and reduced cost can be stably obtained by integrating the acoustooptic medium part and the ultrasonic transducer part. .
[Brief description of the drawings]
FIG. 1 is a perspective view of an acousto-optic device according to a first embodiment of the present invention.
FIG. 2 is an exploded perspective view according to the manufacturing method of the acoustooptic device.
FIG. 3 is a perspective view of the acoustooptic device.
FIG. 4 is a graph showing the linear transmittance at each wavelength for each translucent ceramic used in the acoustooptic device of the present invention.
FIG. 5 is a graph showing a relationship between oxygen concentration in a firing atmosphere and linear transmittance in an example of the translucent ceramic.
FIG. 6 is a perspective view of an acoustooptic device according to a second embodiment of the present invention.
FIG. 7 is an exploded perspective view according to the method for manufacturing the acoustooptic device.
FIG. 8 is a perspective view of the acoustooptic device.
FIG. 9 is a graph showing wavelength dependence on linear transmittance when nickel is added to the translucent ceramic.
FIG. 10 is a perspective view of a laminated block showing another example of one step in the manufacturing method.
FIG. 11 is a perspective view of a conventional acoustooptic device.
[Explanation of symbols]
1 Acousto-optic medium
2 Ultrasonic transducer
3 Internal electrodes
4 External electrode

Claims (5)

An acousto-optic medium unit made of translucent ceramics is provided,
An ultrasonic transducer unit made of piezoelectric ceramics is provided connected to the acoustooptic medium unit,
An internal electrode for generating ultrasonic waves is provided in the ultrasonic transducer unit by exposing one end of the internal electrode and arranging the exposed portions alternately.
A pair of external electrodes are provided for supplying power to each of the internal electrodes;
An acoustooptic device, wherein the acoustooptic medium portion and the ultrasonic transducer portion are integrally formed by firing. The translucent ceramics contains at least one of Ba, Sr, and Ca at the A site, and Sn, Zr, Hf, Ta, Zn, Nb, Sb, Mg, Ti, Al, and rare earths at the B site. The acoustooptic device according to claim 1 , comprising a perovskite crystal structure represented by a general formula ABO ₃ containing at least one kind. The translucent ceramic is Ba [(Sn , Zr) Mg , Ta] O ₃ System, or Ba (Zr , Zn , Ta) O ₃ 3. The acoustooptic device according to claim 1, wherein the main crystal phase is a composite perovskite crystal structure. The acoustooptic device according to any one of claims 1 to 3, wherein the piezoelectric ceramic is at least one selected from the group consisting of barium titanate, PLZT, lithium tantalate, and lithium niobate. A sheet-like first green sheet is produced from the raw material powder of translucent ceramics,
A sheet-like second green sheet is produced from the raw material powder of the piezoelectric ceramic,
Forming an internal electrode on the surface of the second green sheet,
The second green sheet is laminated with each other such that one end of the internal electrode is exposed to the outside and the exposed portions are alternated, and the first green sheet is laminated following the lamination to produce a composite laminate. And
By firing and integrating the composite laminate, an acousto-optic medium portion made of each first green sheet and an ultrasonic transducer portion made of each second green sheet are formed integrally with each other. A method for manufacturing an acoustooptic device.

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