1996 IEEE Ultrasonics Symposium. Proceedings最新文献_第2页

"Ghost" modes in shear mode gallium phosphide and tellurium dioxide Bragg cells 剪切模式磷化镓和二氧化碲Bragg电池中的“鬼影”模式

1996 IEEE Ultrasonics Symposium. Proceedings Pub Date : 1996-11-03 DOI: 10.1109/ULTSYM.1996.584121

D. R. Pape, D.A. Satorius

{"title":"\"Ghost\" modes in shear mode gallium phosphide and tellurium dioxide Bragg cells","authors":"D. R. Pape, D.A. Satorius","doi":"10.1109/ULTSYM.1996.584121","DOIUrl":"https://doi.org/10.1109/ULTSYM.1996.584121","url":null,"abstract":"The fast shear ~1,-1,0 acoustic mode in Gallium Phosphide (GaP) and the slow shear ~110 acoustic mode in Tellurium Dioxide (TeO/sub 2/) are commonly used modes for acousto-optic Bragg cells because of their unique properties-the former because of its anisotropic acoustic \"self-collimating\" property which allows high channel packing density in multichannel devices and the latter because of its anomalously slow velocity which allows the fabrication of long time-aperture devices. When used in spectrum analyzer applications, these acousto-optic Bragg cells must exhibit high spurious-free dynamic range. In Bragg cells using these modes we have experimentally observed unwanted spurious optical diffraction secondary \"ghost\" modes that appear spatially separated from the main first-order optical diffraction. The spatial separation of these modes from the main first-order diffraction, as observed on a photodetector array in an acousto-optic spectrum analyzer arrangement, varies nonlinearly with input frequency and are typically only 15 to 25 dB lower in power than the first-order diffraction. These modes thus severely degrade the spurious-free dynamic range performance of an acousto-optic Bragg cell spectrum analyzer. In the case of GaP we attribute the ghost mode to optical diffraction from an unwanted orthogonally polarized shear acoustic mode excited in the cell. In the case of TeO/sub 2/ we attribute the ghost mode to optical diffraction caused by acousto-optic coupling to an unwanted elliptically polarized optical mode in the cell. Both theoretical and experimental data explaining these phenomena ate presented as well as recommendations for reducing and/or eliminating these deleterious ghost modes.","PeriodicalId":278111,"journal":{"name":"1996 IEEE Ultrasonics Symposium. Proceedings","volume":"98 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1996-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122913593","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}

引用次数: 0

Limited diffraction beams from cylindrical arrays 来自圆柱阵列的有限衍射光束

1996 IEEE Ultrasonics Symposium. Proceedings Pub Date : 1996-11-03 DOI: 10.1109/ULTSYM.1996.584387

D. Allexandre, M. Palmer

引用次数: 0

An ultrasonic phase sensitive method for surface velocity measurements in a liquid 一种测量液体表面速度的超声相敏方法

1996 IEEE Ultrasonics Symposium. Proceedings Pub Date : 1996-11-03 DOI: 10.1109/ULTSYM.1996.584056

D. Royer, O. Casula, O. Bou Matar, F. Patat

引用次数: 6

Real time characterization of elastic variations in palladium films produced by hydrogen adsorption 氢吸附法制备钯膜弹性变化的实时表征

1996 IEEE Ultrasonics Symposium. Proceedings Pub Date : 1996-11-03 DOI: 10.1109/ULTSYM.1996.583977

V. Anisimkin, I. Kotelyanskii, V. I. Fedosov, C. Caliendo, P. Verardi, E. Verona

{"title":"Real time characterization of elastic variations in palladium films produced by hydrogen adsorption","authors":"V. Anisimkin, I. Kotelyanskii, V. I. Fedosov, C. Caliendo, P. Verardi, E. Verona","doi":"10.1109/ULTSYM.1996.583977","DOIUrl":"https://doi.org/10.1109/ULTSYM.1996.583977","url":null,"abstract":"The magnitude and time variations of the SAW propagation velocity /spl Delta/v/v, of the mass and elastic loading, and of the fractional changes in the density /spl Delta//spl rho///spl rho/ and in the elastic modulii /spl Delta/c/sub ij//c/sub ij/ of Pd films are experimentally evaluated at room temperature and atmospheric pressure for 0.1, 0.5, 1% H/sub 2/, 1% CO, 1% N/sub 2/O and 1% NO gas mixtures in pure nitrogen. Two different thermally evaporated Pd films have been tested: one as evaporated, the other one after annealing at 423/spl deg/K and 10/sup -5/ Pa for 15 hours. The annealing is shown to change all set of the parameters. For not annealed films, hydrogen gives rise to large variations in the elastic constants (/spl sime/5-40%) and to an increase in the phase velocity; while for annealed films, it produces small variations in the elastic constants (/spl sime/1-2%) and a decrease in the phase velocity. The difference is attributed to weakly and strongly coupled oxygen preadsorbed in the film. The results obtained can allow an improvement of Pd-based sensors.","PeriodicalId":278111,"journal":{"name":"1996 IEEE Ultrasonics Symposium. Proceedings","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1996-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129612637","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}

引用次数: 11

Preparation of textured LiNbO/sub 3/ thin films by off-axis laser deposition and their characterization 离轴激光沉积制备纹理化LiNbO/ sub3 /薄膜及其表征

1996 IEEE Ultrasonics Symposium. Proceedings Pub Date : 1996-11-03 DOI: 10.1109/ULTSYM.1996.583967

K. Kaemmer, K. Franke, B. Holzapfel, D. Stephan, M. Weihnacht

{"title":"Preparation of textured LiNbO/sub 3/ thin films by off-axis laser deposition and their characterization","authors":"K. Kaemmer, K. Franke, B. Holzapfel, D. Stephan, M. Weihnacht","doi":"10.1109/ULTSYM.1996.583967","DOIUrl":"https://doi.org/10.1109/ULTSYM.1996.583967","url":null,"abstract":"We report on the preparation of lithium niobate thin films on (01.2) and (0001) sapphire and LaAlO/sub 3/ (01.2) single crystalline substrates using off-axis laser deposition. X-ray diffraction in Bragg-Brentano geometry and in a microdiffractometer with an area detector were used to characterize the crystallography, the texture and the lateral homogeneity of the films. We examined the film morphology with atomic force microscopy (AFM) and scanning electron microscopy (SEM). For the preparation of thin films, the deposition temperature, the deposition pressure and the oxygen-Ar ratio of background pressure were varied. The films grow textured and oriented on the substrates used. For thin films on LaAlO/sub 3/ substrates we found only (01.2) reflections of film and substrate in the Bragg-Brentano diffractometer with its selective reflection recording. This suggests that the films are oriented grown and consist of a single LiNbO/sub 3/ phase. Investigations with the microdiffractometer showed that there is also an amount of a LiNb/sub 3/O/sub 8/ textured phase in the films. Thin films deposited on sapphire substrates consist of different mixtures of the LiNbO/sub 3/ phase and the LiNb/sub 3/O/sub 8/ phase depending on the oxygen-Ar ratio of ambient atmosphere. At an oxygen-Ar ratio of 1:4, the films consist mainly of oriented LiNbO/sub 3/. The dielectric polarization and domain structure of the films were investigated by electric scanning force microscopy.","PeriodicalId":278111,"journal":{"name":"1996 IEEE Ultrasonics Symposium. Proceedings","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1996-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128769103","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}

引用次数: 0

Optimum pre-load of surface acoustic wave motor 表面声波电机的最佳预载荷

1996 IEEE Ultrasonics Symposium. Proceedings Pub Date : 1996-11-03 DOI: 10.1109/ULTSYM.1996.583994

M. Kurosawa, M. Takahashi, T. Higuchi

引用次数: 17

The anomalous change of the sound property of electrorheological fluid 电流变流体声特性的异常变化

1996 IEEE Ultrasonics Symposium. Proceedings Pub Date : 1996-11-03 DOI: 10.1109/ULTSYM.1996.584047

T. Xiao, X.R. Zhang

引用次数: 0

Design, fabrication, and application of precise delay lines at 2.45 GHz 2.45 GHz精确延迟线的设计、制造和应用

1996 IEEE Ultrasonics Symposium. Proceedings Pub Date : 1996-11-03 DOI: 10.1109/ULTSYM.1996.583970

C. Ruppel, L. Reindl, S. Berek, U. Knauer, P. Heide, M. Vossiek

{"title":"Design, fabrication, and application of precise delay lines at 2.45 GHz","authors":"C. Ruppel, L. Reindl, S. Berek, U. Knauer, P. Heide, M. Vossiek","doi":"10.1109/ULTSYM.1996.583970","DOIUrl":"https://doi.org/10.1109/ULTSYM.1996.583970","url":null,"abstract":"For years linear optimization algorithms have been used successfully in bandpass filter design. This method has been adopted for the design of dispersive interdigital transducers (IDTs) for pulse compression filters with low time-bandwidth products, and for the design of delay lines with linear phase. Now this method has been extended to the design of dispersive IDTs operating at higher harmonics. As examples, delay lines at 2.45 GHz operating at the fundamental and third harmonic with relative bandwidths up to 30% are presented. The delay lines operating at the fundamental harmonics were fabricated on the rotated cut of LiNbO/sub 3/ and had normal fingers only. The relative height of the metallization was chosen for minimum reflections. Minimum linewidth of 0.3 /spl mu/m was necessary, The delay lines operating at the third harmonic had split fingers for canceling reflections. Therefore minimum linewidths of approximately 0.45 /spl mu/m had to be realized. Measured and calculated frequency responses of these delay lines are compared with each other. Taking advantage of the reported delay lines, a novel FMCW radar system incorporating a 2.45 GHz SAW reference path is established. The proposed SAW based system achieves a higher dynamic range than the conventional FMCW radar sensors.","PeriodicalId":278111,"journal":{"name":"1996 IEEE Ultrasonics Symposium. Proceedings","volume":"81 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1996-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130303619","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}

引用次数: 5

Characteristics of relaxor-based piezoelectric single crystals for ultrasonic transducers 超声换能器用弛豫型压电单晶的特性研究

1996 IEEE Ultrasonics Symposium. Proceedings Pub Date : 1996-11-03 DOI: 10.1109/ULTSYM.1996.584146

Seung-Eek Park, T. Shrout

{"title":"Characteristics of relaxor-based piezoelectric single crystals for ultrasonic transducers","authors":"Seung-Eek Park, T. Shrout","doi":"10.1109/ULTSYM.1996.584146","DOIUrl":"https://doi.org/10.1109/ULTSYM.1996.584146","url":null,"abstract":"For ultrasonic transducers, piezoelectric ceramics offer a range of dielectric constants (K/spl sim/1000-5000), large piezoelectric coefficients (d/sub ij//spl sim/200-700 pC/N), and high electromechanical coupling (k/sub T//spl cong/50%, k/sub 33//spl cong/75%). For several decades, the material of choice has been polycrystalline ceramics based on the solid solution Pb(Zr/sub 1-x/,Ti/sub x/)O/sub 3/ (PZT), compositionally engineered near the morphotropic phase boundary (MPB). The search for alternative MPB systems has led researchers to revisit relaxor-based materials with the general formula Pb(B/sub 1/,B/sub 2/)O/sub 3/ (B/sub 1/:Zn/sup 2+/, Mg/sup 2+/, Sc/sup 3+/, Ni/sup 2+/..., B/sub 2/:Nb/sup 5+/, Ta/sup 5+/...). There are some claims of superior dielectric and piezoelectric performance compared to that of PZT materials. However, when the properties are examined relative to transition temperature (Tc), these differences are not significant. In the single crystal form, however, relaxor-PT materials, represented by Pb(Zn/sub 1/3/Nb/sub 2/3/)O/sub 3/-PbTiO/sub 3/ (PZN-PT), Pb(Mg/sub 1/3/Nb/sub 2/3/)O/sub 3/-PbTiO/sub 3/ (PMN-PT) have been found to exhibit longitudinal coupling coefficients (k/sub 33/)>90%, thickness coupling (k/sub T/)>63%, dielectric constants ranging from 1000 to 5000 with low dielectric loss <1%, and exceptional piezoelectric coefficients d/sub 33/>2000 pC/N, the latter promising for high energy density actuators. For single crystal piezoelectrics to become the next generation material of ultrasonic transducers, further investigation in crystal growth, device fabrication and testing are required.","PeriodicalId":278111,"journal":{"name":"1996 IEEE Ultrasonics Symposium. Proceedings","volume":"73 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1996-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126974480","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}

引用次数: 92

Determining material stiffness using piezoelectric bimorphs 利用压电双晶片测定材料刚度

1996 IEEE Ultrasonics Symposium. Proceedings Pub Date : 1996-11-03 DOI: 10.1109/ULTSYM.1996.584396

M. Coughlin, D. Stamenović, J. G. Smits

引用次数: 3