Pub Date : 1986-12-01DOI: 10.1109/ULTSYM.1986.198838
R. Mueller, W. Robbins, Z.Q. Zhou, E. Rudd
A backprojection imaging capabi 1 i ty has been implemented on a scanning laser acoustic microscope which permits the reconstruction of clear well-defined images of acoustic f eatures which are far below (by tens of acoustic wavelengths) the laser- scanned surface. Several types of test features have been imaged including electron microscope locator g rids afixed to the bottom side of glass slides and etched features (approximately 5 microns deep) on a thick (1 cm) glass block. 100 MHz insonification was used and features with lateral dimensions of roughly 50 microns could be distinguished. Using the same data base, two separate images of a feature could be brought into focus, one corresponding to compressional waves and the other to shear waves. Since the shear and compressional wave data in a conventional SLAM cannot be separated, the two images are superimposed and the out-of- focus image degrades the in-focus image. Possible solutions to this problem using specially designed c over slips will be discussed. The problem of image degradation by multiple reflections and multi-path effects and their mitigation by using pulsed insonification and time-gating will also be discussed.
{"title":"High Resolution Backprojection Imaging with a Scanning Laser Acoustic Microscope","authors":"R. Mueller, W. Robbins, Z.Q. Zhou, E. Rudd","doi":"10.1109/ULTSYM.1986.198838","DOIUrl":"https://doi.org/10.1109/ULTSYM.1986.198838","url":null,"abstract":"A backprojection imaging capabi 1 i ty has been implemented on a scanning laser acoustic microscope which permits the reconstruction of clear well-defined images of acoustic f eatures which are far below (by tens of acoustic wavelengths) the laser- scanned surface. Several types of test features have been imaged including electron microscope locator g rids afixed to the bottom side of glass slides and etched features (approximately 5 microns deep) on a thick (1 cm) glass block. 100 MHz insonification was used and features with lateral dimensions of roughly 50 microns could be distinguished. Using the same data base, two separate images of a feature could be brought into focus, one corresponding to compressional waves and the other to shear waves. Since the shear and compressional wave data in a conventional SLAM cannot be separated, the two images are superimposed and the out-of- focus image degrades the in-focus image. Possible solutions to this problem using specially designed c over slips will be discussed. The problem of image degradation by multiple reflections and multi-path effects and their mitigation by using pulsed insonification and time-gating will also be discussed.","PeriodicalId":345867,"journal":{"name":"IEEE 1986 Ultrasonics Symposium","volume":"132 18 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1986-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127431028","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 : 1986-12-01DOI: 10.1109/ULTSYM.1986.198863
C. Cain, H. Nishiyama, K. Katakura
A composite waveform consisting of the sum of a low-frequency pump sinusoid and a higher frequency probe results in phase modulation of the probe by the pump in nonlinear media. The phase deviation of the probe at the pump frequency can be measured directly o r inferred from measurement of the magnitude of the resulting sum or difference sidebands. The phase deviation (or sideband magnitude) increases linearly with pump pressure and with the slope as a function of the nonlinearity of the medium, thus providing a possible means for determination of B/A. A theory which accounts for attentuation is introduced.
{"title":"On Ultrasonic Techniques for Measurement of the Nonlinear Parameter B/A in Fluid-Like Media","authors":"C. Cain, H. Nishiyama, K. Katakura","doi":"10.1109/ULTSYM.1986.198863","DOIUrl":"https://doi.org/10.1109/ULTSYM.1986.198863","url":null,"abstract":"A composite waveform consisting of the sum of a low-frequency pump sinusoid and a higher frequency probe results in phase modulation of the probe by the pump in nonlinear media. The phase deviation of the probe at the pump frequency can be measured directly o r inferred from measurement of the magnitude of the resulting sum or difference sidebands. The phase deviation (or sideband magnitude) increases linearly with pump pressure and with the slope as a function of the nonlinearity of the medium, thus providing a possible means for determination of B/A. A theory which accounts for attentuation is introduced.","PeriodicalId":345867,"journal":{"name":"IEEE 1986 Ultrasonics Symposium","volume":"19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1986-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124948737","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 : 1986-11-01DOI: 10.1109/ULTSYM.1986.198836
H. Koymen, A. Atalar, T. Ciloglu, M. Onder, C. Uzel, H. Yavuz
{"title":"Imaging Flaws Close to Surface Using Focused Surface Acoustic Waves","authors":"H. Koymen, A. Atalar, T. Ciloglu, M. Onder, C. Uzel, H. Yavuz","doi":"10.1109/ULTSYM.1986.198836","DOIUrl":"https://doi.org/10.1109/ULTSYM.1986.198836","url":null,"abstract":"","PeriodicalId":345867,"journal":{"name":"IEEE 1986 Ultrasonics Symposium","volume":"116 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1986-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121964836","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 : 1986-11-01DOI: 10.1109/ULTSYM.1986.198779
H. Engan, B. Y. Kim, J. Blake, H. Shaw
A novel all-fiber optical frequency shifter, using coupling between the two optical spatial modes in a two-mode glass fiber, is reported. The mode coupling is performed by acoustic flexural waves traveling along the fiber together with the optical waves. The acoustic wavelength for coupling to occur is equal to the beat length between the two optical spatial modes. Flexural waves of high amplitude are excited on the fiber by bonding the thin end of a tapered glass rod to the fiber while a piezoelectric transducer is bonded to the other end of the rod, which has a much larger cross section. A discussion of the acoustic behavior of the system is given. The calculated dispersion of the flexural waves guided by the fiber is compared with experimental measurements. Calculations prescribe the optimum excitation distribution at the thick end of the tapered rod. Experiments have shown 100 percent mode conversion at 8 MHz for 100 mW of electric input power. Measured suppression of both carrier frequency and image sideband was 35 dB.
{"title":"Optical Freouency Shifting in Two-Mode Optical Fibers by Flexural Acoustic Waves","authors":"H. Engan, B. Y. Kim, J. Blake, H. Shaw","doi":"10.1109/ULTSYM.1986.198779","DOIUrl":"https://doi.org/10.1109/ULTSYM.1986.198779","url":null,"abstract":"A novel all-fiber optical frequency shifter, using coupling between the two optical spatial modes in a two-mode glass fiber, is reported. The mode coupling is performed by acoustic flexural waves traveling along the fiber together with the optical waves. The acoustic wavelength for coupling to occur is equal to the beat length between the two optical spatial modes. Flexural waves of high amplitude are excited on the fiber by bonding the thin end of a tapered glass rod to the fiber while a piezoelectric transducer is bonded to the other end of the rod, which has a much larger cross section. A discussion of the acoustic behavior of the system is given. The calculated dispersion of the flexural waves guided by the fiber is compared with experimental measurements. Calculations prescribe the optimum excitation distribution at the thick end of the tapered rod. Experiments have shown 100 percent mode conversion at 8 MHz for 100 mW of electric input power. Measured suppression of both carrier frequency and image sideband was 35 dB.","PeriodicalId":345867,"journal":{"name":"IEEE 1986 Ultrasonics Symposium","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1986-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125483348","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 : 1900-01-01DOI: 10.1109/ULTSYM.1986.198791
G. Kino, J. Fanton, B. Khuri-Yakub
Optical sensors for acoustic waves and photoThey are easy to scan and they can have acoustic effects are used because no mechanical contact needs to be made to the solid material being examined. very good definition. The major disadvantage is that they are extremely insensitive compared to piezoelectric detectors. In photacoustic applications, they are employed to detect modulation of t he surface temperature, surface displacement, and surface slope of a solid, as well as the temperature variation of transparent solids, liquids, and gases. A number of well-established optical detectors, their applications, and their limitations are described. Particular a ttention is given to a new type of Wollaston prism detector, used in combination with a semiconductor laser, which is very simple and exhibits very high sensitivity.
{"title":"Optical Measurements of Acoustic and Photoacoustic Effects","authors":"G. Kino, J. Fanton, B. Khuri-Yakub","doi":"10.1109/ULTSYM.1986.198791","DOIUrl":"https://doi.org/10.1109/ULTSYM.1986.198791","url":null,"abstract":"Optical sensors for acoustic waves and photoThey are easy to scan and they can have acoustic effects are used because no mechanical contact needs to be made to the solid material being examined. very good definition. The major disadvantage is that they are extremely insensitive compared to piezoelectric detectors. In photacoustic applications, they are employed to detect modulation of t he surface temperature, surface displacement, and surface slope of a solid, as well as the temperature variation of transparent solids, liquids, and gases. A number of well-established optical detectors, their applications, and their limitations are described. Particular a ttention is given to a new type of Wollaston prism detector, used in combination with a semiconductor laser, which is very simple and exhibits very high sensitivity.","PeriodicalId":345867,"journal":{"name":"IEEE 1986 Ultrasonics Symposium","volume":"37 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127152174","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 : 1900-01-01DOI: 10.1109/ULTSYM.1986.198784
F. Josse
{"title":"Acoustoelectric Interactions in RBWS in a Piezoelectric-Semiconductor Structure","authors":"F. Josse","doi":"10.1109/ULTSYM.1986.198784","DOIUrl":"https://doi.org/10.1109/ULTSYM.1986.198784","url":null,"abstract":"","PeriodicalId":345867,"journal":{"name":"IEEE 1986 Ultrasonics Symposium","volume":"72 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127367146","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 : 1900-01-01DOI: 10.1109/ULTSYM.1986.198725
M. Barnard, M. Lancaster, E. Paige
In previous papers [1,2] the Slanted Chirped Transducer (SCT) and its performance in a spectrum analyser have been discussed. The SCT's previously described have all been linearly chirped. This paper describes a new form of SCT based on a nonlinear chirp; specifically a chirp which alters in frequency exponentially. A spectrum analyser based on an SCT preserves phase information. The novel feature of the device incorporating the exponentially chirped SCT is that the time delay between input and output is the same for each channel. This means that a wide band signal applied to the SCT can be reconstructed, within the constraints of discrete channels and limited SCT bandwidth, by the summation of the signals from individual output channels. The predicted and observed performance of the new spectrum analyser on Y-cut lithium niobate will be discussed together with applications.
{"title":"The Exponentially Chirped SCT Spectrum Analyser","authors":"M. Barnard, M. Lancaster, E. Paige","doi":"10.1109/ULTSYM.1986.198725","DOIUrl":"https://doi.org/10.1109/ULTSYM.1986.198725","url":null,"abstract":"In previous papers [1,2] the Slanted Chirped Transducer (SCT) and its performance in a spectrum analyser have been discussed. The SCT's previously described have all been linearly chirped. This paper describes a new form of SCT based on a nonlinear chirp; specifically a chirp which alters in frequency exponentially. A spectrum analyser based on an SCT preserves phase information. The novel feature of the device incorporating the exponentially chirped SCT is that the time delay between input and output is the same for each channel. This means that a wide band signal applied to the SCT can be reconstructed, within the constraints of discrete channels and limited SCT bandwidth, by the summation of the signals from individual output channels. The predicted and observed performance of the new spectrum analyser on Y-cut lithium niobate will be discussed together with applications.","PeriodicalId":345867,"journal":{"name":"IEEE 1986 Ultrasonics Symposium","volume":"75 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124705189","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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