The polarizations of diffracted light by ultrasound in isotropic phase of 4-cyano-4'-pentylbiphenyl (5CB) were measured as a function of Raman-Nath parameter. To examine the validity of the theoretical treatments, measurements of the change in the azimuthal angle and the relative phase shift for the Oth and ±lst order diffracted light were carried out. Experimental results are compared with calculated results based on the theory derived by our previous study. The experimental results agree with the theoretical predictions using the material parameters of 5CB in the literature.

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In this paper, accurate measurements of elastic constants of sapphire single crystal are reported. The propagation directions and modes of bulk waves optimal for accurately determining the constants were selected through numerical calculations. Several specimens were prepared from a sapphire single crystal ingot produced by the Bagdasarov method. All of the constants were determined by accurately measuring longitudinal and shear velocities, and density. We clearly detected some significant differences between the measured and published constants. We also confirmed the sign of c_<14> was positive, although it was negative in Wachtman's data.

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We attempted to grow Ta_2O_5 single crystal thin film on a single crystal substrate(X-cut LiTaO_3) by using a linear rapid thermal annealing method. In order to obtain the refractive index of the thin film, m-line method was used. From this result, we proved optical anisotropy of the thin film, and the value of refractive index difference Δ n=0.031 is larger than the value of other optical crystal. In order to obtain photo-elastic constant of the thin film, we measured Laman-Nath diffracted light intensity about LiTaO_3 and (Ta_2O_5/LiTaO_3) , respectively. From these results, photo-elastic constant of the thin film was about 6-10 times than one of LiTaO_3.

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PMN-PT has a dramatically large piezoelectricity. This piezoelectric behavior is fundamentally controlled by the ferroelectric domains called engineered domain structures. A surface electrode pair with 10 μm gap was fabricated on PMN-PT in order to apply electric field in observation plane of AFM. Domain structure was evaluated by ultrasonic atomic force microscopy (UAFM) and lateral piezoresponse force microscopy (LPFM). In UAFM, resonance frequency decreased on domain boundaries imaged by LPFM, due to the reduction of contact stiffness. Moreover, subsurface domain boundary tilted with respect to the observation plane was observed, although it was not imaged by LPFM. As a result of applying electric field, switching with motions of domain boundaries was observed. A surface electrode pair is useful to evaluate domain behavior in ferroelectrics.

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Since the communication networks are recently getting to be high-speed broadband, the demand of higher frequency band is increasing up to millimeter-wave bands. Actually, millimeter-waves have already been applied for wireless LAN and so on. In such systems, it is strictly necessary to develop low-loss, wide-band and high attenuation level band-pass filters. Indeed, various kind of millimeter-wave band-pass filter has been proposed. The crystal substrate is suited for millimeter wave substrate because of low dielectric loss and high stability in the millimeter wave region. In this paper, a novel millimeter band-pass filter using crystal substrate is proposed and fabricated. And we examine the transmission characteristics and the temperature behaviors of the proposed filter.

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Electrode materials applied to Film Bulk Acoustic Resonator (FBAR) and Solidly Mounted Resonator (SMR) play key role in order to realize low-loss filters. This paper describes analysis of AIN-based FBAR regarding effects of acoustic impedance. It is found that coupling factor (k^2) and loss are influenced by acoustic impedance and mainly dominated by Young's modulus.

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This report presents a novel method to obtain BAW resonators with different resonant frequencies on the same substrate without additional tuning layer. The resonant frequency of each resonator is adjusted by forming numerous holes of dimensions smaller than the acoustic wavelength on the top electrode. Here we demonstrate that the resonant frequency can be adjusted, by controlling the area of the holes, within a range of 170 MHz on a BAW resonator with the resonant frequency of 1.9 GHz. The results indicate that BAW filters can be tuned by means of photolithographic patterns, and therefore the manufacturing cost is lower than a conventional BAW filter with additional tuning layer.

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In frequency adjustment of the crystal resonator by ion beam etching, the phenomenon which frequency shifts immediately after etching arose, and it became the big cause which barred utilization. So, theoretical analysis of this frequency change was conducted. Temperature distribution change of the crystal resonator at the time of ion beam irradiation was calculated by the FDM. Thermal stress distribution was calculated from temperature distribution, and change of resonance frequency was calculated from change of the elastic constant. Analysis carrying out about AT, BT, and SC cut, calculation and an experimental result were well in agreement. Therefore, it turned out that thermal stress arises in temperature distribution change produced by ion beam irradiation, an elastic constant changes, and frequency changes.

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This paper explains the results of the research conducted on the QCM biosensor with the AT cut crystal unit as the sensor in experiments carry out in liquid. In the design of the crystal sensor, the strong Energy Trap Effect is applied. A newly developed sensor system that combines both the analog and digital frequency measurement principle is used to measure the short-term stability and the long-term stability. Based on these results together with the application of the Immunoassay method, the antigen-antibody reaction is observed and the dependence of frequency change on antibody concentration is examined. As a result, it is confirmed that the newly developed experiment system and the crystal sensor can be applied to the QCM biosensor.

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The construction of the frequency-change-type single crystal silicon 2-axis acceleration sensor is proposed and designed by the finite element method. The sensor element is composed of the two developed flexural vibrators, mass and support bars. The volume is about 4.0×4.2×0.5 mm^3. The 1st out-of-plane mode is used in the vibrator. The resonance frequency of the vibrator is 80.834 kHz. The analyzed relationship between the applied acceleration and the resonance frequency change becomes linear in this sensor element. The sensor sensitivity of approximately 468 ppm/G is realized. When the acceleration is applied, the motion of mass is linear along the x and y axes respectively. As a future subject, the sensor sensitivity should be improved by using a bent type support bar.

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Scanning nonlinear dielectric microscopy (SNDM) with super-high resolution is described. At first, experimental results for ferroelectric domain and the visualization of charge stored in flash memories are shown, following the description of theory and principle of SNDM. Next, higher-order nonlinear dielectric imaging method and non-contact SNDM (nc-SNDM) are proposed. Using this nc-SNDM technique, the first achievement of atomic resolution in capacitance measurement is successfully demonstrated. In addition to this technique, a new 3D-type of SNDM to measure the 3D distribution of ferroelectric polarization has been developed. Finally, a very high density ferroelectric data storage based on SNDM with the density of 10 T-bits/inch^2 is demonstrated.

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The basic studies on time reversal for underwater acoustic technologies have been carried out by authors, and the method of the acoustic communication using time reversal with adaptive equalizer was proposed. This technique will be applied to long horizontal communication in the deep ocean with an autonomous underwater vehicle (AUV). The experiment was executed in the area at the depth of 1,000m in Suruga-bay. The 500Hz projectors were used, and the range between the focus and the time-reversal array (TRA) was 10 km. Unfortunately, the projector of the TRA side had a breakdown, so it was impossible to execute active time-reversal communication. However, experiments of passive time-reversal communication could be achieved. It was verified that the proposed method enables to assure the communication channel with the TRA of 20 elements.

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Acoustic fields through an acoustic lens, that is a prototype of multi acoustic lens system, were measured in a water tank to evaluate its performance, but it didn't make sense because of shortage of measurable space in the tank. For better understanding the experiment results, those results were compared to simulated acoustic fields by Parabolic Equation Method under same as the experiment conditions.

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We have deposited PZT poly-crystalline film on the titanium substrate using hydrothermal method, and have developed transducers for ultrasound probes. In this time, the 10 MHz medical miniature 1-dimensional array type ultrasound probe with hydrothermally PZT poly-crystalline films is developed. After sputtering of titanium on the surface of hydroxyapatite substrate, the titanium film was etched using photolithography method to form 1-dimensional titanium film electrodes array. Then we could succeed fabricating the miniature 1-dimensional array type ultrasound probe by hydrothermal method. Transmitted ultrasound pulse from 10 MHz commercial ultrasound probe was received by the trial fabricated 1-dimentional array type ultrasound probe. The fabrication process of the probe, received waveform and power spectrum etc are reported in this paper.

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The effects of fine metal oxide particles, BaSO_4, Al_2O_3, TiO_2, ZrO_2, Fe_O_3 and Yb_2O_3 on the acoustic properties of silicone rubber have been investigated, in order to develop an acoustic lens material with a low acoustic attenuation. Silicone rubber doped with Yb_2O_3 powder having nanoparticle size of 16 nm showed a lower acoustic attenuation than silicone rubber doped with other powders. The silicone rubber doped with Yb_2O_3 powder showed a density of 1.63 x 10^3 kg/m^3, a sound velocity of 816 m/s, an acoustic impedance Z_<33> of 1.33 x 10^6 kg/m^2s, an acoustic attenuation of 0.93 dB/mmMHz at 37℃. The low sound velocity and low acoustic attenuation of the lens material contribute to make a low loss acoustic lens for medical array probe application.

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In vitro calf liver experiment showed that the thermal parameter k (i.e., expressed by temperature coefficients of US speed and volume change) was inhomogeneous as well as dependent on temperature and thermal exposure time. To enable the planning of the thermal treatment, on the basis of the updating of the thermal parameter k using temperature references, we need to reconstruct the tissue thermal conductivity, capacity and difrusivity.

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Atherosclerotic change of the arterial wall leads to a significant change in its elasticity. For assessment of elasticity, accurate measurement of the arterial wall deformation is required. We developed a correlation-based method, the phased tracking method, to measure the regional strain due to heartbeat. In the displacement estimation by such a phase-sensitive method, the displacement estimates are biased due to the change in the center frequency of RF echo. One of reasons for the change in the center frequency is the interference of echoes from scatterers in the wall. To reduce this error, the translational motion was compensated in estimation of strain in this study.

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Small sized surface acoustic wave (SAW) duplexer for wide band CDMA with good temperature coefficient of frequency (TCF) has been required. But the size of conventional SAW duplexer is 3.8×3.8mm^2 size and that TCF is not good (-80ppm/℃). By using flattened SiO_2/Cu-electrode/YX-LiNbO_3, SAW duplexer having a low insertion loss and a good TCP has been realized.

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High-frequency (GHz range) Diamond SAW resonators with good temperature stability have been developed by using a SiO_2/ZnO/diamond structure. According to Lesson's model, in order to obtain low phase noise, the resonators should have large power durability regarding resonators in oscillator circuit. This paper describes the improvements in power durability that were made by improving the structure of the diamond SAW resonators. The improved structure differs from the conventional structure only in that it has an additional thin film of ZnO between the SiO_2 and IDTs. It was found that the resonator of the improved structure was capable of withstanding input power 20 dB higher than that of the conventional structure.

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The propagation characteristics of surface acoustic wave (SAW) along a solid surface vary considerably depending on the ambient environment. Therefore, SAW devices are used as sensors in variety of fields. In particular, SAW propagating in the shear horizontal (SH) mode only has components for which particle displacement are parallel to the surface. This means that even in a liquid they propagate without loss of energy. Sensors that utilize such waves are thus suitable for sensing the characteristics of liquids. In this study, a flow-type liquid sensor using a 2-port SH-SAW resonator was constructed and used to measure the concentration of methanol. The results showed that the SAW sensor was very suitable to sensing the flow liquids.

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We have developed the piezoelectric ceramics for high power applications. We focused efforts on (1-x)PbTiO_3-Pb(Mg_<1/3>Nb_<2/3>)O_3 (x=1.00, 0.95, 0.90) electrostrictive ceramics which haven't almost domain wall causing the increase of energy loss such as heat generations. We investigated DC bias field dependence on high-power characteristics for PbTiO_3-Pb(Mg_<1/3>Nb_<2/3>)O_3 electrostrictive ceramics using electrical transient response method. The Q_m for the paraelectric crystal phase composition at room temperature maintains over 5000 at high stress level under dc bias field. Furthermore, the piezoelectric d_<31> constant is almost the same as that of hard lead zirconate titanate (PZT). Electrostrictive ceramics are therefore superior electromechanical vibrator material for high power application.

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We propose a twin-T-type quartz resonance circuit in which the null frequency can be changed by adjusting the applied voltage ratio. In the circuit construction, two sets of T-type circuits are used in which a quartz resonator is placed in the shunt branch and the output of each circuit settles in one terminal. The changeable frequency range exceeds the limit of the electromechanical coupling factor of the piezoelectric resonator used when the resonance frequency of a coil and a capacitor in the series branch of the twin-T-type circuit is set to almost the same value as the resonance frequency of the resonators used in the twin-T-type circuit.

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Recently, the research that applies piezoelectric generator or harvester to the power supply of electronic devices that work by a low power is paid to attention. RFID tags are the key electronic device to realize the ubiquitous computing. Periodic exchange of the batteries is needed though an active type RFID tag has a very low power requirement and a long communication distance. In this study, the possibility of the application of piezoelectric generation to active type RFID tag is described. As an example of application of RFID using piezoelectric generator, the system to secure safety of going to school and leaving school of the child is proposed and the experimental results are presented.

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In this study, we propose a communication system for wearable computing devices using ultrasonic information transmission. Ultrasonic is safe for the human body and does not cause malfunctioning of electronic equipments. Our study deals with an experimental model system for preliminary development and the analysis of its results. For the results of the prototype experiment assumed a wristwatch type computer, a transmission speed of 115.2 kbps is obtained between a forefinger and a wrist. Additionally, the speed is realized between two persons who hold hands. The proposed method can be applied various practical systems.

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