Pub Date : 1995-11-07DOI: 10.1109/ULTSYM.1995.495759
F. Forsberg, Y.Q. Wu, I. Makin, J. Srinivasan, Wenhua Wang, M. Wheatley
Quantitative characterization of a new ultrasound contrast media ST68 has been performed, ST68 is a sonicated mixture of nonionic surfactants (Span-type and Tween-type), consisting of stabilized microbubbles with a mean diameter of 3.8 /spl mu/m and a concentration of 7.1/spl times/10/sup 8/ bubbles/mL. In vitro a pulsatile flow system was used to acquire digitized RF A-lines. The acoustic properties of ST68, as a function of time, frequency and dose, were calculated. Backscatter changed nonlinearly with dose; maximum was 12.5 dB/spl plusmn/1.0 dB for a 0.4 mL dose. Attenuation reached approximately 22.5 dB/cm for dosages above 0.4 mL. In vivo intravenous injections were given to three rabbits (dosage: 0.01-0.23 mL/kg). A clear increase in flow signal intensity was observed for 1-2 minutes. An in vivo dose response curve was calculated from the audio signals of a 10 MHz cuff transducer placed around the distal aorta. Maximum enhancement was 18.3 dB/spl plusmn/3.13 dB for a 0.13 mL/kg dose. In conclusion, ST68 is capable of producing marked vascular enhancement. Its acoustic properties have been characterized in vitro and in vivo.
{"title":"In vitro and in vivo characterization of a new surfactant stabilized ultrasound contrast media","authors":"F. Forsberg, Y.Q. Wu, I. Makin, J. Srinivasan, Wenhua Wang, M. Wheatley","doi":"10.1109/ULTSYM.1995.495759","DOIUrl":"https://doi.org/10.1109/ULTSYM.1995.495759","url":null,"abstract":"Quantitative characterization of a new ultrasound contrast media ST68 has been performed, ST68 is a sonicated mixture of nonionic surfactants (Span-type and Tween-type), consisting of stabilized microbubbles with a mean diameter of 3.8 /spl mu/m and a concentration of 7.1/spl times/10/sup 8/ bubbles/mL. In vitro a pulsatile flow system was used to acquire digitized RF A-lines. The acoustic properties of ST68, as a function of time, frequency and dose, were calculated. Backscatter changed nonlinearly with dose; maximum was 12.5 dB/spl plusmn/1.0 dB for a 0.4 mL dose. Attenuation reached approximately 22.5 dB/cm for dosages above 0.4 mL. In vivo intravenous injections were given to three rabbits (dosage: 0.01-0.23 mL/kg). A clear increase in flow signal intensity was observed for 1-2 minutes. An in vivo dose response curve was calculated from the audio signals of a 10 MHz cuff transducer placed around the distal aorta. Maximum enhancement was 18.3 dB/spl plusmn/3.13 dB for a 0.13 mL/kg dose. In conclusion, ST68 is capable of producing marked vascular enhancement. Its acoustic properties have been characterized in vitro and in vivo.","PeriodicalId":268177,"journal":{"name":"1995 IEEE Ultrasonics Symposium. Proceedings. An International Symposium","volume":"49 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1995-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132682765","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1995-11-07DOI: 10.1109/ULTSYM.1995.495569
S. Rooth, A. Rønnekleiv
The design of narrowband SAW filters involves the calculation of SAW propagation in transducers which are long compared to the square of their apertures in wavelengths. To increase design accuracy, it is of high importance to model diffraction effects in these transducer structures. We present a method for calculating diffraction of both forward and backward propagating SAWs, which are coupled. Hence, both SPUDT filters and inline resonator filters can be described by diffraction. The simulation of diffraction is performed by dividing the transducers into tracks (across the transducers' aperture) as for the analysis of apodized weighted transducers. By allowing for a direct acoustic coupling between the tracks, we simulate diffraction by a coupling theory. This theory is capable of describing the transducers by a uniform surface condition diffraction theory or as waveguides.
{"title":"The application of pseudoinverse matrices for diffraction calculation of SAW propagation in transducers","authors":"S. Rooth, A. Rønnekleiv","doi":"10.1109/ULTSYM.1995.495569","DOIUrl":"https://doi.org/10.1109/ULTSYM.1995.495569","url":null,"abstract":"The design of narrowband SAW filters involves the calculation of SAW propagation in transducers which are long compared to the square of their apertures in wavelengths. To increase design accuracy, it is of high importance to model diffraction effects in these transducer structures. We present a method for calculating diffraction of both forward and backward propagating SAWs, which are coupled. Hence, both SPUDT filters and inline resonator filters can be described by diffraction. The simulation of diffraction is performed by dividing the transducers into tracks (across the transducers' aperture) as for the analysis of apodized weighted transducers. By allowing for a direct acoustic coupling between the tracks, we simulate diffraction by a coupling theory. This theory is capable of describing the transducers by a uniform surface condition diffraction theory or as waveguides.","PeriodicalId":268177,"journal":{"name":"1995 IEEE Ultrasonics Symposium. Proceedings. An International Symposium","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1995-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133125847","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1995-11-07DOI: 10.1109/ULTSYM.1995.495624
V. Anisimkin, M. Penza, S. A. Maksimov, L. Vasanelli
Uncoated SAW delay lines performing as thermal probes are applied for detection of gases and gas flows. Analysis of the forced convection is performed for 13 analytes in linear approximation by neglecting their chemical interaction with the ambient. Experimental detection is performed for H/sub 2/, He, Ar, CH/sub 4/, NH/sub 3/, N/sub 2/, O/sub 2/, dry air, using SAW delay lines on SiO/sub 2/, LiNbO/sub 3/, Bi/sub 12/GeO/sub 20/, Bi/sub 12/SiO/sub 20/, at operating temperatures T=25-165/spl deg/C and frequencies f=21-263 MHz. SAW responses are measured as a function of concentration n, flow rate u, temperature coefficient of velocity (TCV) and temperature T. Efficient selectivity and monitoring of the responses are demonstrated by a proper selection of TCV and T. Detection of 0.35% CH/sub 4/, 0.25% H/sub 2/ and 0.1% NH/sub 3/ in N/sub 2/ is performed. Linear output for u=50-2000 ml/min is obtained.
{"title":"SAW delay lines for thermal detection of gases and gas flows","authors":"V. Anisimkin, M. Penza, S. A. Maksimov, L. Vasanelli","doi":"10.1109/ULTSYM.1995.495624","DOIUrl":"https://doi.org/10.1109/ULTSYM.1995.495624","url":null,"abstract":"Uncoated SAW delay lines performing as thermal probes are applied for detection of gases and gas flows. Analysis of the forced convection is performed for 13 analytes in linear approximation by neglecting their chemical interaction with the ambient. Experimental detection is performed for H/sub 2/, He, Ar, CH/sub 4/, NH/sub 3/, N/sub 2/, O/sub 2/, dry air, using SAW delay lines on SiO/sub 2/, LiNbO/sub 3/, Bi/sub 12/GeO/sub 20/, Bi/sub 12/SiO/sub 20/, at operating temperatures T=25-165/spl deg/C and frequencies f=21-263 MHz. SAW responses are measured as a function of concentration n, flow rate u, temperature coefficient of velocity (TCV) and temperature T. Efficient selectivity and monitoring of the responses are demonstrated by a proper selection of TCV and T. Detection of 0.35% CH/sub 4/, 0.25% H/sub 2/ and 0.1% NH/sub 3/ in N/sub 2/ is performed. Linear output for u=50-2000 ml/min is obtained.","PeriodicalId":268177,"journal":{"name":"1995 IEEE Ultrasonics Symposium. Proceedings. An International Symposium","volume":"4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1995-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134409225","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1995-11-07DOI: 10.1109/ULTSYM.1995.495708
D. Cathignol, O. Sapozhnikov, J. Zhang, J. Chapelon
The present report compares acoustical fields radiated in water from two focused transducers of the same geometrical parameters (aperture diameter 100 mm, focal length 100 mm, resonance frequency 1 MHz), but made of different materials (PZT piezoceramic and piezocomposite). Both continuous wave and pulsed regimes of transducer excitation were used. A discrepancy between the O'Neil theory (1949) and experiment was noticed, which was essential in the case of the PZT radiator and of little importance for the piezocomposite source. It is shown that this disagreement is accounted for by Lamb waves propagating in the piezoceramic transducer material. O'Neil theory is not applicable to describe the pressure field, as long as the effect of Lamb waves is not taken into account for PZT transducers. On the contrary, O'Neil theory is able to describe approximately the pressure field of highly focused piezocomposite transducers.
{"title":"Comparison of acoustical fields radiated from PZT piezoceramic and piezocomposite highly focused transducers","authors":"D. Cathignol, O. Sapozhnikov, J. Zhang, J. Chapelon","doi":"10.1109/ULTSYM.1995.495708","DOIUrl":"https://doi.org/10.1109/ULTSYM.1995.495708","url":null,"abstract":"The present report compares acoustical fields radiated in water from two focused transducers of the same geometrical parameters (aperture diameter 100 mm, focal length 100 mm, resonance frequency 1 MHz), but made of different materials (PZT piezoceramic and piezocomposite). Both continuous wave and pulsed regimes of transducer excitation were used. A discrepancy between the O'Neil theory (1949) and experiment was noticed, which was essential in the case of the PZT radiator and of little importance for the piezocomposite source. It is shown that this disagreement is accounted for by Lamb waves propagating in the piezoceramic transducer material. O'Neil theory is not applicable to describe the pressure field, as long as the effect of Lamb waves is not taken into account for PZT transducers. On the contrary, O'Neil theory is able to describe approximately the pressure field of highly focused piezocomposite transducers.","PeriodicalId":268177,"journal":{"name":"1995 IEEE Ultrasonics Symposium. Proceedings. An International Symposium","volume":"19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1995-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134640067","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1995-11-07DOI: 10.1109/ULTSYM.1995.495600
A. Hachigo, D. Malocha, S. M. Richie
The surface acoustic wave (SAW) filter properties of ZnO/diamond/Si structure are calculated including velocity dispersion. It is well known that the pole width of a SAW filter response and the number of electrodes have a reciprocal relation for bulk piezoelectric materials. However, the pole width of layered structures tends to be narrower than that of expected bulk SAW devices and the reason is due to the velocity dispersion of layered structures. The pole width of layered structures was calculated by the delta function model including the velocity dispersion and was compared with the experimental results. The dispersion effect is also calculated by using the Smith's equivalent circuit model. The results of this analysis are presented and agree well with the experimental results.
{"title":"ZnO/diamond/Si SAW filter properties including velocity dispersion","authors":"A. Hachigo, D. Malocha, S. M. Richie","doi":"10.1109/ULTSYM.1995.495600","DOIUrl":"https://doi.org/10.1109/ULTSYM.1995.495600","url":null,"abstract":"The surface acoustic wave (SAW) filter properties of ZnO/diamond/Si structure are calculated including velocity dispersion. It is well known that the pole width of a SAW filter response and the number of electrodes have a reciprocal relation for bulk piezoelectric materials. However, the pole width of layered structures tends to be narrower than that of expected bulk SAW devices and the reason is due to the velocity dispersion of layered structures. The pole width of layered structures was calculated by the delta function model including the velocity dispersion and was compared with the experimental results. The dispersion effect is also calculated by using the Smith's equivalent circuit model. The results of this analysis are presented and agree well with the experimental results.","PeriodicalId":268177,"journal":{"name":"1995 IEEE Ultrasonics Symposium. Proceedings. An International Symposium","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1995-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133092432","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1995-11-07DOI: 10.1109/ULTSYM.1995.495543
A. El Habti, F. Bastien, E. Bigler, T. Thorvaldsson
Previous works in the frequency range of 5 to 23 MHz have shown that the limitation of the Q-factor in high performance quartz bulk wave resonators at room temperature is mainly due to the intrinsic acoustic losses. However by cooling down the device to liquid helium (4.2 K) the contribution of acoustic losses vanishes, thus enabling an increase of the Q-factor, by one order of magnitude and the evaluation of other sources of losses. In the present paper, a similar approach has been followed for high frequency Rayleigh wave resonators at 416 MHz. It is shown that for surface waves propagating in a state of the art quartz SAW resonator, the main source of losses is also due to intrinsic acoustic losses. By cooling down the device below 30 K, the dependence of the Q-factor versus temperature follows a behavior in T/sup 4/, characteristic of internal acoustic losses, and then reaches a plateau region at about 4-10 K. High Q factors in the range of 1.5/spl times/10/sup 5/ have been obtained at 4.2 K for 416 MHz devices, yielding a Q.f product in the range of 7/spl times/10/sup 14/ to be compared to the best results obtained with cooled bulk wave devices : 2.4/spl times/10/sup 14/.
{"title":"Experimental study of SAW quartz resonators at very low temperature","authors":"A. El Habti, F. Bastien, E. Bigler, T. Thorvaldsson","doi":"10.1109/ULTSYM.1995.495543","DOIUrl":"https://doi.org/10.1109/ULTSYM.1995.495543","url":null,"abstract":"Previous works in the frequency range of 5 to 23 MHz have shown that the limitation of the Q-factor in high performance quartz bulk wave resonators at room temperature is mainly due to the intrinsic acoustic losses. However by cooling down the device to liquid helium (4.2 K) the contribution of acoustic losses vanishes, thus enabling an increase of the Q-factor, by one order of magnitude and the evaluation of other sources of losses. In the present paper, a similar approach has been followed for high frequency Rayleigh wave resonators at 416 MHz. It is shown that for surface waves propagating in a state of the art quartz SAW resonator, the main source of losses is also due to intrinsic acoustic losses. By cooling down the device below 30 K, the dependence of the Q-factor versus temperature follows a behavior in T/sup 4/, characteristic of internal acoustic losses, and then reaches a plateau region at about 4-10 K. High Q factors in the range of 1.5/spl times/10/sup 5/ have been obtained at 4.2 K for 416 MHz devices, yielding a Q.f product in the range of 7/spl times/10/sup 14/ to be compared to the best results obtained with cooled bulk wave devices : 2.4/spl times/10/sup 14/.","PeriodicalId":268177,"journal":{"name":"1995 IEEE Ultrasonics Symposium. Proceedings. An International Symposium","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1995-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129126988","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1995-11-07DOI: 10.1109/ULTSYM.1995.495863
A. Webb, N. Smith, D. S. Ellis, W. O’Brien
The aim of this study was to investigate the feasibility of using fluorine based magnetic resonance to measure accurately hepatic heating from a focused ultrasound transducer in rats. This new method uses the temperature dependence of the difference in fluorine chemical shifts within a single molecule to provide internal compensation for complicating physiological effects. Female Sprague-Dawley rats were exposed to 5 minutes of CW irradiation at 1.37 MHz from a focused transducer. Theoretical calculations based on the monopole source solution to the bio-heat transfer equation gave a volume-averaged temperature rise of 2.1/spl deg/C. Preliminary experiments using protein encapsulated perfluorooctylbromide targeted to the liver gave an empirical rise of 2.0/spl plusmn/0.4/spl deg/C.
{"title":"Non-invasive in-vivo temperature mapping of ultrasound heating using fluorine-based magnetic resonance imaging agents","authors":"A. Webb, N. Smith, D. S. Ellis, W. O’Brien","doi":"10.1109/ULTSYM.1995.495863","DOIUrl":"https://doi.org/10.1109/ULTSYM.1995.495863","url":null,"abstract":"The aim of this study was to investigate the feasibility of using fluorine based magnetic resonance to measure accurately hepatic heating from a focused ultrasound transducer in rats. This new method uses the temperature dependence of the difference in fluorine chemical shifts within a single molecule to provide internal compensation for complicating physiological effects. Female Sprague-Dawley rats were exposed to 5 minutes of CW irradiation at 1.37 MHz from a focused transducer. Theoretical calculations based on the monopole source solution to the bio-heat transfer equation gave a volume-averaged temperature rise of 2.1/spl deg/C. Preliminary experiments using protein encapsulated perfluorooctylbromide targeted to the liver gave an empirical rise of 2.0/spl plusmn/0.4/spl deg/C.","PeriodicalId":268177,"journal":{"name":"1995 IEEE Ultrasonics Symposium. Proceedings. An International Symposium","volume":"211 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1995-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134399295","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1995-11-07DOI: 10.1109/ULTSYM.1995.495825
A. Hernandez, O. Basset, I. Dautraix, I. Magnin, C. Favre, G. Giménez
Presents a stereoscopic visualization technique applied to three-dimensional (3-D) ultrasonic data of the breast. A motorized mechanical set-up has been designed to provide a series of two-dimensional (2-D) parallel echographic slices of the breast from the regular translation of a linear phased array transducer. During the acquisition step, the breast is compressed between a plane support and a plexiglass plate to avoid breast motions. Two simulated conical X-ray projections of the acquired volume are computed under two slightly different points of view. These two projections constitute the ultrasonic pair which is displayed to restitute the depth of the 3-D breast tumours.
{"title":"Stereoscopic visualization of 3D ultrasonic data for the diagnosis improvement of breast tumors","authors":"A. Hernandez, O. Basset, I. Dautraix, I. Magnin, C. Favre, G. Giménez","doi":"10.1109/ULTSYM.1995.495825","DOIUrl":"https://doi.org/10.1109/ULTSYM.1995.495825","url":null,"abstract":"Presents a stereoscopic visualization technique applied to three-dimensional (3-D) ultrasonic data of the breast. A motorized mechanical set-up has been designed to provide a series of two-dimensional (2-D) parallel echographic slices of the breast from the regular translation of a linear phased array transducer. During the acquisition step, the breast is compressed between a plane support and a plexiglass plate to avoid breast motions. Two simulated conical X-ray projections of the acquired volume are computed under two slightly different points of view. These two projections constitute the ultrasonic pair which is displayed to restitute the depth of the 3-D breast tumours.","PeriodicalId":268177,"journal":{"name":"1995 IEEE Ultrasonics Symposium. Proceedings. An International Symposium","volume":"114 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1995-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132357939","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1995-11-07DOI: 10.1109/ULTSYM.1995.495568
S. Jen, C. Hartmann
A unique technique for direct measurement of SAW dispersion relation using a phase-sensitive laser probe is presented. This technique is based on analysis of fixed-frequency longitudinal scans across a reflection grating structure. The first major step is purely experimental, in which the various contributing waves are identified by examining the respective spatial spectrum of the measured profiles. For a leaky wave grating, this yields directly the real part of the wavenumbers of both the counter-propagating leaky waves and the Rayleigh wave as functions of frequency. Standard signal processing techniques can then be applied to allow extraction and separate examination of the individual waves. The second major step is to compare the measured real part of the leaky wave wavenumbers and the extracted profiles with theoretical models for verification and/or reduction of the model parameters. By comparing individually extracted profiles at fixed frequency points, the velocity, reflectivity, as well as propagation loss, can be verified and/or obtained with high degree of accuracy. Results from leaky wave grating on 64/spl deg/ LiNbO/sub 3/ are reported. These include the first direct observation of frequency dependent propagation loss due to bulk scattering. Comparison with the latest Coupling-of-Modes modeling is also discussed. Using the same measurement and data reduction methodology with a long transducer, independent measurements of the transduction coupling strength and the bulk radiation loss appear feasible. Furthermore, this technique should be equally applicable to purely Rayleigh wave and surface transverse wave grating structures.
{"title":"Direct measurement of SAW dispersion relation by laser probe","authors":"S. Jen, C. Hartmann","doi":"10.1109/ULTSYM.1995.495568","DOIUrl":"https://doi.org/10.1109/ULTSYM.1995.495568","url":null,"abstract":"A unique technique for direct measurement of SAW dispersion relation using a phase-sensitive laser probe is presented. This technique is based on analysis of fixed-frequency longitudinal scans across a reflection grating structure. The first major step is purely experimental, in which the various contributing waves are identified by examining the respective spatial spectrum of the measured profiles. For a leaky wave grating, this yields directly the real part of the wavenumbers of both the counter-propagating leaky waves and the Rayleigh wave as functions of frequency. Standard signal processing techniques can then be applied to allow extraction and separate examination of the individual waves. The second major step is to compare the measured real part of the leaky wave wavenumbers and the extracted profiles with theoretical models for verification and/or reduction of the model parameters. By comparing individually extracted profiles at fixed frequency points, the velocity, reflectivity, as well as propagation loss, can be verified and/or obtained with high degree of accuracy. Results from leaky wave grating on 64/spl deg/ LiNbO/sub 3/ are reported. These include the first direct observation of frequency dependent propagation loss due to bulk scattering. Comparison with the latest Coupling-of-Modes modeling is also discussed. Using the same measurement and data reduction methodology with a long transducer, independent measurements of the transduction coupling strength and the bulk radiation loss appear feasible. Furthermore, this technique should be equally applicable to purely Rayleigh wave and surface transverse wave grating structures.","PeriodicalId":268177,"journal":{"name":"1995 IEEE Ultrasonics Symposium. Proceedings. An International Symposium","volume":"43 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1995-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133297887","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1995-11-07DOI: 10.1109/ULTSYM.1995.495608
E.A. Kolosovsky, A. Tsarev, I. B. Yakovkin
We present detailed investigations of a novel interferometric method for measuring the surface acoustic wave (SAW) velocity, based on diffraction of two optical beams on SAW. The method advantages are high accuracy, availability and opportunity of simultaneous measurement of the phase and the group velocities of SAW, and their dispersion. The experimental error for the phase and the group SAW velocity measuring is estimated as 0.5 m/s and 3 m/s, respectively.
{"title":"Two optical beams method for the SAW velocity measurements in anisotropic structures","authors":"E.A. Kolosovsky, A. Tsarev, I. B. Yakovkin","doi":"10.1109/ULTSYM.1995.495608","DOIUrl":"https://doi.org/10.1109/ULTSYM.1995.495608","url":null,"abstract":"We present detailed investigations of a novel interferometric method for measuring the surface acoustic wave (SAW) velocity, based on diffraction of two optical beams on SAW. The method advantages are high accuracy, availability and opportunity of simultaneous measurement of the phase and the group velocities of SAW, and their dispersion. The experimental error for the phase and the group SAW velocity measuring is estimated as 0.5 m/s and 3 m/s, respectively.","PeriodicalId":268177,"journal":{"name":"1995 IEEE Ultrasonics Symposium. Proceedings. An International Symposium","volume":"31 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1995-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131889778","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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