Pub Date : 1900-01-01DOI: 10.1364/pcta.1988.efd109
A. E. Smart, J. Abbiss
This paper discusses a laser anemometer based on projected light sheets and using a sequence of non-linear discrimination stages in both optics and electronics. Innovative digital correlation techniques yield significantly more accurate transit time measurements than can be obtained from equivalent fringe or two-spot systems. Enhancements of signal processing based upon a priori knowledge of the optical sheet definition and the measurement environment result in up to an order of magnitude increase in accuracy.
{"title":"Discrimination Techniques for a Highly Accurate Laser-Sheet Anemometer","authors":"A. E. Smart, J. Abbiss","doi":"10.1364/pcta.1988.efd109","DOIUrl":"https://doi.org/10.1364/pcta.1988.efd109","url":null,"abstract":"This paper discusses a laser anemometer based on projected light sheets and using a sequence of non-linear discrimination stages in both optics and electronics. Innovative digital correlation techniques yield significantly more accurate transit time measurements than can be obtained from equivalent fringe or two-spot systems. Enhancements of signal processing based upon a priori knowledge of the optical sheet definition and the measurement environment result in up to an order of magnitude increase in accuracy.","PeriodicalId":371566,"journal":{"name":"Photon Correlation Techniques and Applications","volume":"12 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":"117098690","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: 10.1364/pcta.1988.pcmdr14
J. Shaumeyer, R. Gammon
We have performed an experiment to test our understanding of the run time, T, necessary to achieve a specified precision in the value of the intensity coherence time, τc, extracted from correlation functions taken in the strong signal limit, and to test predictions for the values of some experimental parameters that optimize the precision. Using ensembles of 10 correlation functions taken at 5 different choices of sample time, we found that the ensemble estimators for the error in τc were well described by the expression δτ/τ c =4.2/T/τ c , in agreement with the work of Degiorgio and Lastovka (1971). The sample times used were chosen so that the number of coherence times spanned by the 128 channels of the correlator, α, covered the range 1 ≤ α ≤ 16; in this range, we found no evidence of a minimum in δτ/τc to suggest an optimum value of α. These results were independent of whether we used three-parameter or two-parameter least-squares fits to extract τc. However, we did find that the two fits gave systematically different values of τc, and both show a similar dependence on α.
我们进行了一个实验，以测试我们对运行时间T的理解，T是在强信号极限中从相关函数中提取的强度相干时间τc值达到指定精度所必需的，并测试对优化精度的一些实验参数值的预测。使用5种不同采样时间下的10个相关函数的集合，我们发现τc误差的集合估计可以用δτ/τ c =4.2/T/τ c的表达式很好地描述，这与Degiorgio和Lastovka(1971)的工作一致。选取采样次数，使相关器的128个通道所跨越的相干次数α在1≤α≤16范围内;在这个范围内，我们发现没有证据表明δτ/τc有一个最小值来表示α的最佳值。这些结果与我们是否使用三参数或两参数最小二乘拟合来提取τc无关。然而，我们确实发现这两种拟合给出了系统不同的τc值，并且都显示出对α的相似依赖。
{"title":"Optimizing Fitting Statistics in Photon Correlation Spectroscopy","authors":"J. Shaumeyer, R. Gammon","doi":"10.1364/pcta.1988.pcmdr14","DOIUrl":"https://doi.org/10.1364/pcta.1988.pcmdr14","url":null,"abstract":"We have performed an experiment to test our understanding of the run time, T, necessary to achieve a specified precision in the value of the intensity coherence time, τc, extracted from correlation functions taken in the strong signal limit, and to test predictions for the values of some experimental parameters that optimize the precision. Using ensembles of 10 correlation functions taken at 5 different choices of sample time, we found that the ensemble estimators for the error in τc were well described by the expression \u0000δτ/τ\u0000 c\u0000 =4.2/T/τ\u0000 c\u0000 , in agreement with the work of Degiorgio and Lastovka (1971). The sample times used were chosen so that the number of coherence times spanned by the 128 channels of the correlator, α, covered the range 1 ≤ α ≤ 16; in this range, we found no evidence of a minimum in δτ/τc to suggest an optimum value of α. These results were independent of whether we used three-parameter or two-parameter least-squares fits to extract τc. However, we did find that the two fits gave systematically different values of τc, and both show a similar dependence on α.","PeriodicalId":371566,"journal":{"name":"Photon Correlation Techniques and Applications","volume":"22 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":"128002134","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: 10.1364/pcta.1988.pcs153
R. Carr, A. Stansfield, J. Rarity, R. G. Brown, D. Clarke, T. Atkinson
Photon Correlation Spectroscopy has been applied to the routine monitoring of proteins eluting off liquid chromatographic separation systems. The technique has been configured as an on-line, in situ detector capable of remote analyses using fibre optic technology. Analyses of flowing protein samples has been demonstrated and its use in process biochemistry as a quality assurance monitor is discussed.
{"title":"On-Line Liquid Chromatography Detection by Photon Correlation Spectroscopy","authors":"R. Carr, A. Stansfield, J. Rarity, R. G. Brown, D. Clarke, T. Atkinson","doi":"10.1364/pcta.1988.pcs153","DOIUrl":"https://doi.org/10.1364/pcta.1988.pcs153","url":null,"abstract":"Photon Correlation Spectroscopy has been applied to the routine monitoring of proteins eluting off liquid chromatographic separation systems. The technique has been configured as an on-line, in situ detector capable of remote analyses using fibre optic technology. Analyses of flowing protein samples has been demonstrated and its use in process biochemistry as a quality assurance monitor is discussed.","PeriodicalId":371566,"journal":{"name":"Photon Correlation Techniques and Applications","volume":"2 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":"130430271","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: 10.1364/pcta.1988.pcmdr2
E. Pike
The photon correlation technique has a special feature relating to the accuracy achieved in typical experiments on the data points. With modern sources and detectors experiments are virtually noiseless except for the discrete photon nature of the light itself. This fact has given rise to a special study of the information content of such data, particularly in the case of photon correlation spectroscopy (or PCS) (1) in which light scattering from diffusing macromolecules produces an exponential photon correlation function if a single species or size of particle is present, and a superposition of exponentials or Laplace transform of a distribution of such radii or sizes. In this case it very quickly became apparent that the "information content" of the photon correlation function, even with very high accuracy in the data points themselves, was very low and that inversion of such data rarely provided more than about three independent data points on the distribution function required. Equivalently only the first three central moments of the distribution could be reasonably recovered.
{"title":"Singular Function Techniques for Photon Correlation Data Reduction","authors":"E. Pike","doi":"10.1364/pcta.1988.pcmdr2","DOIUrl":"https://doi.org/10.1364/pcta.1988.pcmdr2","url":null,"abstract":"The photon correlation technique has a special feature relating to the accuracy achieved in typical experiments on the data points. With modern sources and detectors experiments are virtually noiseless except for the discrete photon nature of the light itself. This fact has given rise to a special study of the information content of such data, particularly in the case of photon correlation spectroscopy (or PCS) (1) in which light scattering from diffusing macromolecules produces an exponential photon correlation function if a single species or size of particle is present, and a superposition of exponentials or Laplace transform of a distribution of such radii or sizes. In this case it very quickly became apparent that the \"information content\" of the photon correlation function, even with very high accuracy in the data points themselves, was very low and that inversion of such data rarely provided more than about three independent data points on the distribution function required. Equivalently only the first three central moments of the distribution could be reasonably recovered.","PeriodicalId":371566,"journal":{"name":"Photon Correlation Techniques and Applications","volume":"5 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":"114268131","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: 10.1364/pcta.1988.dsopp202
M. Teich
The generation of nonclassical light has recently received a great deal of attention because three forms of it have now been observed in the laboratory: antibunched light, photon-number-squeezed (or sub-Poisson) light, and quadrature-squeezed light. These characteristics may, but need not, accompany each other in any given light source. Nonclassical light has been produced in experiments using resonance fluorescence, the Franck-Hertz effect, parametric interact ions, and semiconductor light sources. It is likely to be useful in providing new insights in various physical and biological processes, and in applications such as lightwave communications. Some of the characteristics, methods of generation, and expected uses of squeezed light will be addressed.
{"title":"Squeezed Light","authors":"M. Teich","doi":"10.1364/pcta.1988.dsopp202","DOIUrl":"https://doi.org/10.1364/pcta.1988.dsopp202","url":null,"abstract":"The generation of nonclassical light has recently received a great deal of attention because three forms of it have now been observed in the laboratory: antibunched light, photon-number-squeezed (or sub-Poisson) light, and quadrature-squeezed light. These characteristics may, but need not, accompany each other in any given light source. Nonclassical light has been produced in experiments using resonance fluorescence, the Franck-Hertz effect, parametric interact ions, and semiconductor light sources. It is likely to be useful in providing new insights in various physical and biological processes, and in applications such as lightwave communications. Some of the characteristics, methods of generation, and expected uses of squeezed light will be addressed.","PeriodicalId":371566,"journal":{"name":"Photon Correlation Techniques and Applications","volume":"88 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":"127906205","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: 10.1364/pcta.1988.dsopp207
I. Grant, G.H. Smith
The last decade has seeen the evolution of particle image velocimetry, often refered to as speckle velocimetry, as a new and powerful technique for obtaining simultaneous measurements of the two in-plane components of fluid velocity at all points on a two-dimensional illuminated "sheet". The sheet is produced by passing the output from a pulsed (or chopped CW) laser through a combination of spherical and cylindrical lenses. The sheet is viewed along a normal so that a sequence of stroboscopic images are obtained of the developing flow. These are recorded either on photographic plate or by video camera for post-experiment image processing.
{"title":"Recent Advances in Pulsed Laser(\"Speckle\") Velocimetry","authors":"I. Grant, G.H. Smith","doi":"10.1364/pcta.1988.dsopp207","DOIUrl":"https://doi.org/10.1364/pcta.1988.dsopp207","url":null,"abstract":"The last decade has seeen the evolution of particle image velocimetry, often refered to as speckle velocimetry, as a new and powerful technique for obtaining simultaneous measurements of the two in-plane components of fluid velocity at all points on a two-dimensional illuminated \"sheet\". The sheet is produced by passing the output from a pulsed (or chopped CW) laser through a combination of spherical and cylindrical lenses. The sheet is viewed along a normal so that a sequence of stroboscopic images are obtained of the developing flow. These are recorded either on photographic plate or by video camera for post-experiment image processing.","PeriodicalId":371566,"journal":{"name":"Photon Correlation Techniques and Applications","volume":"98 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":"116882365","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}
The paper describes a technique for the investigation of flows through the inlet ports of internal combustion engines using photon-correlation laser velocimetry and refractive-index matching. The technique is applied to the measurement of the flow through a helical inlet port.
{"title":"Photon Correlation Velocimetry Measurements of Inlet Port Flows","authors":"M. Yianneskis, M. Tindal, R. Cheung","doi":"10.1364/pcta.1988.efd90","DOIUrl":"https://doi.org/10.1364/pcta.1988.efd90","url":null,"abstract":"The paper describes a technique for the investigation of flows through the inlet ports of internal combustion engines using photon-correlation laser velocimetry and refractive-index matching. The technique is applied to the measurement of the flow through a helical inlet port.","PeriodicalId":371566,"journal":{"name":"Photon Correlation Techniques and Applications","volume":"10 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":"121343193","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: 10.1364/pcta.1988.pcs163
L. Lading, J. Mann, R. V. Edwards
The photon statistics of light scattered by a surface is investigated. It is shown how the photon correlation function depends on the mode of the light scattering configuration and on the space-time correlation of the surface structure. The uncertainties of the estimated photon correlation are evaluated.
{"title":"Photon Statistics of Light Scattered by a Liquid Gas Interface","authors":"L. Lading, J. Mann, R. V. Edwards","doi":"10.1364/pcta.1988.pcs163","DOIUrl":"https://doi.org/10.1364/pcta.1988.pcs163","url":null,"abstract":"The photon statistics of light scattered by a surface is investigated. It is shown how the photon correlation function depends on the mode of the light scattering configuration and on the space-time correlation of the surface structure. The uncertainties of the estimated photon correlation are evaluated.","PeriodicalId":371566,"journal":{"name":"Photon Correlation Techniques and Applications","volume":"54 6 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":"132429232","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}
Following a detailed review of practical aspects of photon-correlation laser-Doppler velocimetry, automotive applications are surveyed with emphasis on broad experimental and interpretive concerns common to unsteady flows and confined environments. Such situations typically permit only limited optical access and thereby place a premium on efficient operation with weak (single-photon) signals in the presence of considerable noise. Fast, robust data-acquisition and -reduction techniques that minimize user intervention are described. The survey of automotive applications concentrates on turbulent in-cylinder flow fields and combustion, but briefly includes wind-tunnel and soot-sizing measurements.
{"title":"Photon-Correlation Laser Velocimetry in Reciprocating-Engine Research","authors":"T. Fansler","doi":"10.1364/pcta.1988.efd54","DOIUrl":"https://doi.org/10.1364/pcta.1988.efd54","url":null,"abstract":"Following a detailed review of practical aspects of photon-correlation laser-Doppler velocimetry, automotive applications are surveyed with emphasis on broad experimental and interpretive concerns common to unsteady flows and confined environments. Such situations typically permit only limited optical access and thereby place a premium on efficient operation with weak (single-photon) signals in the presence of considerable noise. Fast, robust data-acquisition and -reduction techniques that minimize user intervention are described. The survey of automotive applications concentrates on turbulent in-cylinder flow fields and combustion, but briefly includes wind-tunnel and soot-sizing measurements.","PeriodicalId":371566,"journal":{"name":"Photon Correlation Techniques and Applications","volume":"1 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":"116236530","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: 10.1364/pcta.1988.dsopp200
K. Schätzel
Dynamic light scattering experiments on colloidal particles or similar systems typically use one of two optical systems which have been termed homodyne and heterodyne setups, respectively. The homodyne system uses a single illuminating laser beam. Light from the measurement volume is detected coherently, i. e. through a small detector aperture. As a result, fluctuating interference or light beats are observed due to relative motion of the scattering centers with respect to each other. For noninteracting particles, the coherence time of the detected light readily yields the coefficient of diffusion and hence the particle sizes - today the most important application of dynamic light scattering.
{"title":"Introduction to Photon Correlation Techniques and Applications","authors":"K. Schätzel","doi":"10.1364/pcta.1988.dsopp200","DOIUrl":"https://doi.org/10.1364/pcta.1988.dsopp200","url":null,"abstract":"Dynamic light scattering experiments on colloidal particles or similar systems typically use one of two optical systems which have been termed homodyne and heterodyne setups, respectively. The homodyne system uses a single illuminating laser beam. Light from the measurement volume is detected coherently, i. e. through a small detector aperture. As a result, fluctuating interference or light beats are observed due to relative motion of the scattering centers with respect to each other. For noninteracting particles, the coherence time of the detected light readily yields the coefficient of diffusion and hence the particle sizes - today the most important application of dynamic light scattering.","PeriodicalId":371566,"journal":{"name":"Photon Correlation Techniques and Applications","volume":"99 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":"128771279","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}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：