Pub Date : 1998-09-01DOI: 10.1088/0963-9659/7/5/017
M. Carbon, N. Lauinger, J. Schwab
We present a general solution of the wave equation, obtained by the four-dimensional spectral method, for diffraction of a plane monochromatic light wave by a three-dimensional (3D) phase grating layer of finite thickness. As an example, we consider spherical particles in 3D phase gratings with orthogonal and hexagonal geometry. Conditions for the strong self-imaging of a 3D grating layer and for the weak self-imaging of a two-dimensional (2D) grating are formulated and investigated. Intensity distributions for diffracted light in planes of positive and negative self-imaging and in a plane of lowest contrast are computed and compared for 2D and 3D gratings. Some aspects of the Talbot and Lau effects for 2D and 3D phase gratings are discussed.
{"title":"SELF-IMAGING OF THREE-DIMENSIONAL PHASE GRATINGS","authors":"M. Carbon, N. Lauinger, J. Schwab","doi":"10.1088/0963-9659/7/5/017","DOIUrl":"https://doi.org/10.1088/0963-9659/7/5/017","url":null,"abstract":"We present a general solution of the wave equation, obtained by the four-dimensional spectral method, for diffraction of a plane monochromatic light wave by a three-dimensional (3D) phase grating layer of finite thickness. As an example, we consider spherical particles in 3D phase gratings with orthogonal and hexagonal geometry. Conditions for the strong self-imaging of a 3D grating layer and for the weak self-imaging of a two-dimensional (2D) grating are formulated and investigated. Intensity distributions for diffracted light in planes of positive and negative self-imaging and in a plane of lowest contrast are computed and compared for 2D and 3D gratings. Some aspects of the Talbot and Lau effects for 2D and 3D phase gratings are discussed.","PeriodicalId":20787,"journal":{"name":"Pure and Applied Optics: Journal of The European Optical Society Part A","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1998-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86539447","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 : 1998-09-01DOI: 10.1088/0963-9659/7/5/005
V. I. Tatarskii
{"title":"An intuitive introduction to the Wolf effect","authors":"V. I. Tatarskii","doi":"10.1088/0963-9659/7/5/005","DOIUrl":"https://doi.org/10.1088/0963-9659/7/5/005","url":null,"abstract":"","PeriodicalId":20787,"journal":{"name":"Pure and Applied Optics: Journal of The European Optical Society Part A","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1998-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78666291","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 : 1998-09-01DOI: 10.1088/0963-9659/7/5/028
R. Martínez-Herrero, P. Mejías
From the expansion of a partially coherent axially symmetric beam in terms of Laguerre-Gauss functions, we investigate the degree of accuracy reached by approaching the exact field by means of the lower-order terms of the above series. The accuracy is evaluated analytically as a function of both the number of terms of the expansion and the (measurable) second-order intensity moments of the beam, namely, the beam width and the so-called beam quality factor .
{"title":"Truncation error of the Laguerre-Gauss expansion of axially symmetric beams in terms of second-order intensity moments","authors":"R. Martínez-Herrero, P. Mejías","doi":"10.1088/0963-9659/7/5/028","DOIUrl":"https://doi.org/10.1088/0963-9659/7/5/028","url":null,"abstract":"From the expansion of a partially coherent axially symmetric beam in terms of Laguerre-Gauss functions, we investigate the degree of accuracy reached by approaching the exact field by means of the lower-order terms of the above series. The accuracy is evaluated analytically as a function of both the number of terms of the expansion and the (measurable) second-order intensity moments of the beam, namely, the beam width and the so-called beam quality factor .","PeriodicalId":20787,"journal":{"name":"Pure and Applied Optics: Journal of The European Optical Society Part A","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1998-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80840677","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 : 1998-09-01DOI: 10.1088/0963-9659/7/5/018
A. Lohmann, D. Mendlovic, G. Shabtay
If a wave is laterally periodic, then it is also longitudinally periodic. Nevertheless, lateral periodicity is not needed for longitudinal periodicity. Lateral quasi-periodicity is a more general case and sufficient for longitudinal periodicity. These results can be drawn from the Helmholtz equation, if the light is quasi-monochromatic and spatially coherent. For partially coherent light, similar results can be deduced from the Wolf equations. The triple correlation of a complex amplitude obeys a pair of wave equations, which are constructed exactly like the Wolf equations. Hence, the same laws on periodicity are valid. We present a historical and systematic view of all of those periodicity laws.
{"title":"Talbot (1836), Montgomery (1967), Lau (1948) and Wolf (1955) on periodicity in optics","authors":"A. Lohmann, D. Mendlovic, G. Shabtay","doi":"10.1088/0963-9659/7/5/018","DOIUrl":"https://doi.org/10.1088/0963-9659/7/5/018","url":null,"abstract":"If a wave is laterally periodic, then it is also longitudinally periodic. Nevertheless, lateral periodicity is not needed for longitudinal periodicity. Lateral quasi-periodicity is a more general case and sufficient for longitudinal periodicity. These results can be drawn from the Helmholtz equation, if the light is quasi-monochromatic and spatially coherent. For partially coherent light, similar results can be deduced from the Wolf equations. The triple correlation of a complex amplitude obeys a pair of wave equations, which are constructed exactly like the Wolf equations. Hence, the same laws on periodicity are valid. We present a historical and systematic view of all of those periodicity laws.","PeriodicalId":20787,"journal":{"name":"Pure and Applied Optics: Journal of The European Optical Society Part A","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1998-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90514505","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 : 1998-09-01DOI: 10.1088/0963-9659/7/5/026
A. Devaney, E. A. Marengo
The theory and results concerning the class of spherically symmetric non-radiating sources and fields established in an earlier paper by Gamliel et al are generalized to the non-spherically symmetric case. A procedure is described for constructing bases for the spaces of all non-radiating sources and associated fields confined to a spherical volume. An example is presented illustrating the developed theory.
{"title":"A method for specifying non-radiating, monochromatic, scalar sources and their fields","authors":"A. Devaney, E. A. Marengo","doi":"10.1088/0963-9659/7/5/026","DOIUrl":"https://doi.org/10.1088/0963-9659/7/5/026","url":null,"abstract":"The theory and results concerning the class of spherically symmetric non-radiating sources and fields established in an earlier paper by Gamliel et al are generalized to the non-spherically symmetric case. A procedure is described for constructing bases for the spaces of all non-radiating sources and associated fields confined to a spherical volume. An example is presented illustrating the developed theory.","PeriodicalId":20787,"journal":{"name":"Pure and Applied Optics: Journal of The European Optical Society Part A","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1998-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91548468","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 : 1998-09-01DOI: 10.1088/0963-9659/7/5/023
Bingquan Chen, J. Stamnes, K. Stamnes
With applications in medical diagnosis in mind we apply the theory of diffraction tomography to diffuse photon density waves in a random medium. We consider the two-and-a-half-dimensional (2.5D) problem in which a two-dimensional (2D) object is illuminated by diffuse photon density waves from a point source. Both the forward problem and the inverse problem are discussed, and a reconstruction algorithm based on the weak-scattering approximation is presented together with computer simulations.
{"title":"Reconstruction algorithm for diffraction tomography of diffuse photon density waves in a random medium","authors":"Bingquan Chen, J. Stamnes, K. Stamnes","doi":"10.1088/0963-9659/7/5/023","DOIUrl":"https://doi.org/10.1088/0963-9659/7/5/023","url":null,"abstract":"With applications in medical diagnosis in mind we apply the theory of diffraction tomography to diffuse photon density waves in a random medium. We consider the two-and-a-half-dimensional (2.5D) problem in which a two-dimensional (2D) object is illuminated by diffuse photon density waves from a point source. Both the forward problem and the inverse problem are discussed, and a reconstruction algorithm based on the weak-scattering approximation is presented together with computer simulations.","PeriodicalId":20787,"journal":{"name":"Pure and Applied Optics: Journal of The European Optical Society Part A","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1998-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83326146","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 : 1998-09-01DOI: 10.1088/0963-9659/7/5/010
Y. Harada, T. Asakura
Dynamics and light-scattering properties of Brownian particles in colloidal suspensions under the influence of the radiation pressure force of an illuminating laser beam are investigated by means of computer simulations using the Fokker-Planck equation and generalized Lorenz-Mie theory. Dynamic behaviour of the particles and a temporal correlation function of intensity fluctuations of the light scattered by these particles are calculated for various factors of particle size and power of the illuminating laser beam. Results of the simulations support the experimental observations of deformation in the temporal correlation functions of the scattered light and their dependences on the size of the particles and the power of the laser. From simulation results for the dynamics of particles, it is found that these changes in the correlation function arise from suppression of the random motion of the particles in the radial direction of the laser beam and induction of an average uniform motion in the beam propagation direction.
{"title":"Dynamics and dynamic light-scattering properties of Brownian particles under laser radiation pressure","authors":"Y. Harada, T. Asakura","doi":"10.1088/0963-9659/7/5/010","DOIUrl":"https://doi.org/10.1088/0963-9659/7/5/010","url":null,"abstract":"Dynamics and light-scattering properties of Brownian particles in colloidal suspensions under the influence of the radiation pressure force of an illuminating laser beam are investigated by means of computer simulations using the Fokker-Planck equation and generalized Lorenz-Mie theory. Dynamic behaviour of the particles and a temporal correlation function of intensity fluctuations of the light scattered by these particles are calculated for various factors of particle size and power of the illuminating laser beam. Results of the simulations support the experimental observations of deformation in the temporal correlation functions of the scattered light and their dependences on the size of the particles and the power of the laser. From simulation results for the dynamics of particles, it is found that these changes in the correlation function arise from suppression of the random motion of the particles in the radial direction of the laser beam and induction of an average uniform motion in the beam propagation direction.","PeriodicalId":20787,"journal":{"name":"Pure and Applied Optics: Journal of The European Optical Society Part A","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1998-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88701841","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 : 1998-07-01DOI: 10.1088/0963-9659/7/4/010
V. N. Parygin, A. V. Vershoubskiy
The peculiarities of collinear acousto-optical diffraction of Gaussian optical beams by an acoustic pulse of finite dimensions with an arbitrary temporal envelope is investigated theoretically. The system of two first-order equations that describe the Fourier spectra of transmitted and diffracted light beams and of an acoustic pulse which are propagating in the same direction is deduced. Linear frequency modulation of an acoustic pulse is considered. The filter transmission curves during the collinear diffraction by acoustic pulses with temporal envelopes described by Gaussian and sinc(x) functions is calculated. The dependence of the acousto-optical cell transmission bandwidth on both pulse and crystal length variation is studied.
{"title":"Collinear diffraction of Gaussian optical beams by an acoustic pulse","authors":"V. N. Parygin, A. V. Vershoubskiy","doi":"10.1088/0963-9659/7/4/010","DOIUrl":"https://doi.org/10.1088/0963-9659/7/4/010","url":null,"abstract":"The peculiarities of collinear acousto-optical diffraction of Gaussian optical beams by an acoustic pulse of finite dimensions with an arbitrary temporal envelope is investigated theoretically. The system of two first-order equations that describe the Fourier spectra of transmitted and diffracted light beams and of an acoustic pulse which are propagating in the same direction is deduced. Linear frequency modulation of an acoustic pulse is considered. The filter transmission curves during the collinear diffraction by acoustic pulses with temporal envelopes described by Gaussian and sinc(x) functions is calculated. The dependence of the acousto-optical cell transmission bandwidth on both pulse and crystal length variation is studied.","PeriodicalId":20787,"journal":{"name":"Pure and Applied Optics: Journal of The European Optical Society Part A","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1998-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81376427","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 : 1998-07-01DOI: 10.1088/0963-9659/7/4/019
A. Fix, V. Weiss, G. Ehret
Any detailed understanding of the role of water vapour in the global climate system requires precise measurements in the atmosphere with high temporal and spatial resolution. A technique that is appropriate to deliver these data is airborne differential absorption lidar (DIAL) applied in the near-infrared spectral range. In order to accurately determine atmospheric water vapour concentrations by means of the DIAL technique tunability and spectral properties of the lidar transmitter are very important. It is demonstrated that the spectral and energy requirements are achieved using optical parametric oscillators (OPOs) that are line-narrowed by the technique of injection seeding with radiation from dye lasers or from laser diodes. When the OPO is unseeded its spectral width is broad enough to suffer only negligible absorption from the absorption lines. Therefore, the unseeded OPO radiation can be used for off-line measurement, which simplifies the DIAL set-up significantly. In addition, the laser diodes were employed to measure line parameters of a selected absorption line in the near-IR. Their precise determination is important in order to make accurate DIAL measurements.
{"title":"Injection-seeded optical parametric oscillator for airborne water vapour DIAL","authors":"A. Fix, V. Weiss, G. Ehret","doi":"10.1088/0963-9659/7/4/019","DOIUrl":"https://doi.org/10.1088/0963-9659/7/4/019","url":null,"abstract":"Any detailed understanding of the role of water vapour in the global climate system requires precise measurements in the atmosphere with high temporal and spatial resolution. A technique that is appropriate to deliver these data is airborne differential absorption lidar (DIAL) applied in the near-infrared spectral range. In order to accurately determine atmospheric water vapour concentrations by means of the DIAL technique tunability and spectral properties of the lidar transmitter are very important. It is demonstrated that the spectral and energy requirements are achieved using optical parametric oscillators (OPOs) that are line-narrowed by the technique of injection seeding with radiation from dye lasers or from laser diodes. When the OPO is unseeded its spectral width is broad enough to suffer only negligible absorption from the absorption lines. Therefore, the unseeded OPO radiation can be used for off-line measurement, which simplifies the DIAL set-up significantly. In addition, the laser diodes were employed to measure line parameters of a selected absorption line in the near-IR. Their precise determination is important in order to make accurate DIAL measurements.","PeriodicalId":20787,"journal":{"name":"Pure and Applied Optics: Journal of The European Optical Society Part A","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1998-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89611217","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 : 1998-07-01DOI: 10.1088/0963-9659/7/4/021
R. Huffaker, Paul A. Reveley
Diode-pumped solid-state pulsed coherent laser radar systems have recently been developed at Coherent Technologies, Inc., for the remote measurement of atmospheric wind fields. Flashlamp-pumped systems have been utilized since 1990 for obtaining wind field measurements. These flashlamp-pumped lidar systems have been applied to wind profiling, aircraft-wake vortex measurements, airport wind shear and gust front monitoring, military cargo air drops and many other applications. The diode-pumped coherent lidar systems currently available are capable of near turnkey operation. The Tm:YAG laser transceivers operate at with output pulse energies of 1-10 mJ with PRFs of 1000 to 100 Hz, respectively. Range resolutions of 30-75 m are typical. A real-time lidar signal processor has also been developed for collecting and analysing laser radar (lidar) data. The signal processor is based on a commercial PC architecture and offers a real-time data acquisition, analysis, display, recording and playback environment. Wind measurements and overall system performance results will be presented. Wind measurement performance, for a variety of applications, is presented using the flashlamp- and diode-pumped coherent lidars including measured wind profiles from ground and on aircraft, wake vortex tracking results, and example flows over mountain terrain.
{"title":"Solid-state coherent laser radar wind field measurement systems","authors":"R. Huffaker, Paul A. Reveley","doi":"10.1088/0963-9659/7/4/021","DOIUrl":"https://doi.org/10.1088/0963-9659/7/4/021","url":null,"abstract":"Diode-pumped solid-state pulsed coherent laser radar systems have recently been developed at Coherent Technologies, Inc., for the remote measurement of atmospheric wind fields. Flashlamp-pumped systems have been utilized since 1990 for obtaining wind field measurements. These flashlamp-pumped lidar systems have been applied to wind profiling, aircraft-wake vortex measurements, airport wind shear and gust front monitoring, military cargo air drops and many other applications. The diode-pumped coherent lidar systems currently available are capable of near turnkey operation. The Tm:YAG laser transceivers operate at with output pulse energies of 1-10 mJ with PRFs of 1000 to 100 Hz, respectively. Range resolutions of 30-75 m are typical. A real-time lidar signal processor has also been developed for collecting and analysing laser radar (lidar) data. The signal processor is based on a commercial PC architecture and offers a real-time data acquisition, analysis, display, recording and playback environment. Wind measurements and overall system performance results will be presented. Wind measurement performance, for a variety of applications, is presented using the flashlamp- and diode-pumped coherent lidars including measured wind profiles from ground and on aircraft, wake vortex tracking results, and example flows over mountain terrain.","PeriodicalId":20787,"journal":{"name":"Pure and Applied Optics: Journal of The European Optical Society Part A","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1998-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91425813","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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