Author: George O. REYNOLDS
Publisher:
ISBN:
Category :
Languages : en
Pages : 79
Book Description
Diffraction by apertures illuminated by partially coherent light, diffraction by apertures containing random phase disturbances, experimental demonstration of the ergodic hypothesis, and the concept of cross spectral purity are considered. In diffraction experiments using partially coherent illumination, it is observed that as the ratio of aperture size to coherence interval increases (i.e., the illumination becomes less coherent) the sharp minima present in the diffraction pattern disappear and a shifting of the minima occurs. The results are compared with existing theories, and the agreement is excellent. It is experimentally shown that random phase disturbances placed in the diffracting aperture distort an individual diffraction pattern. In the corresponding ensemble-averaged experiment, the distortion is reduced and the diffraction pattern is more readily identified. A dynamical model of lycopodium particles suspended in water demonstrated the equivalence of time and ensemble averaging (ergodic hypothesis). The ensemble-averaged results agree quantitatively with theoretical calculations. In investigating the concept of cross spectral purity (J. Opt. Soc. Am. 51:1342 (1961)), it is shown that quasi monochromaticity is synonymous with spectral purity and that spectral impurity is synonymous with polychromaticity. (Author).
Optical Studies of Partially Coherent Diffraction and the Ergodic Hypothesis
Author: George O. REYNOLDS
Publisher:
ISBN:
Category :
Languages : en
Pages : 79
Book Description
Diffraction by apertures illuminated by partially coherent light, diffraction by apertures containing random phase disturbances, experimental demonstration of the ergodic hypothesis, and the concept of cross spectral purity are considered. In diffraction experiments using partially coherent illumination, it is observed that as the ratio of aperture size to coherence interval increases (i.e., the illumination becomes less coherent) the sharp minima present in the diffraction pattern disappear and a shifting of the minima occurs. The results are compared with existing theories, and the agreement is excellent. It is experimentally shown that random phase disturbances placed in the diffracting aperture distort an individual diffraction pattern. In the corresponding ensemble-averaged experiment, the distortion is reduced and the diffraction pattern is more readily identified. A dynamical model of lycopodium particles suspended in water demonstrated the equivalence of time and ensemble averaging (ergodic hypothesis). The ensemble-averaged results agree quantitatively with theoretical calculations. In investigating the concept of cross spectral purity (J. Opt. Soc. Am. 51:1342 (1961)), it is shown that quasi monochromaticity is synonymous with spectral purity and that spectral impurity is synonymous with polychromaticity. (Author).
Publisher:
ISBN:
Category :
Languages : en
Pages : 79
Book Description
Diffraction by apertures illuminated by partially coherent light, diffraction by apertures containing random phase disturbances, experimental demonstration of the ergodic hypothesis, and the concept of cross spectral purity are considered. In diffraction experiments using partially coherent illumination, it is observed that as the ratio of aperture size to coherence interval increases (i.e., the illumination becomes less coherent) the sharp minima present in the diffraction pattern disappear and a shifting of the minima occurs. The results are compared with existing theories, and the agreement is excellent. It is experimentally shown that random phase disturbances placed in the diffracting aperture distort an individual diffraction pattern. In the corresponding ensemble-averaged experiment, the distortion is reduced and the diffraction pattern is more readily identified. A dynamical model of lycopodium particles suspended in water demonstrated the equivalence of time and ensemble averaging (ergodic hypothesis). The ensemble-averaged results agree quantitatively with theoretical calculations. In investigating the concept of cross spectral purity (J. Opt. Soc. Am. 51:1342 (1961)), it is shown that quasi monochromaticity is synonymous with spectral purity and that spectral impurity is synonymous with polychromaticity. (Author).
Technical Abstract Bulletin
Scientific and Technical Aerospace Reports
OAR Cumulative Index of Research Results
Author: United States. Air Force. Office of Aerospace Research
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 586
Book Description
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 586
Book Description
OAR Quarterly Index of Current Research Results
Author: United States. Air Force. Office of Aerospace Research
Publisher:
ISBN:
Category : Aeronautics, Military
Languages : en
Pages : 576
Book Description
Publisher:
ISBN:
Category : Aeronautics, Military
Languages : en
Pages : 576
Book Description
OAR Cumulative Index of Research Results
Government-wide Index to Federal Research & Development Reports
Author:
Publisher:
ISBN:
Category : Government publications
Languages : en
Pages : 1654
Book Description
Publisher:
ISBN:
Category : Government publications
Languages : en
Pages : 1654
Book Description
Journal of Research
Author: United States. National Bureau of Standards
Publisher:
ISBN:
Category : Radio
Languages : en
Pages : 1354
Book Description
Publisher:
ISBN:
Category : Radio
Languages : en
Pages : 1354
Book Description
Diffraction
Author: M. Françon
Publisher: Elsevier
ISBN: 1483185729
Category : Science
Languages : en
Pages : 152
Book Description
Diffraction: Coherence in Optics presents a detailed account of the course on Fraunhofer diffraction phenomena, studied at the Faculty of Science in Paris. The publication first elaborates on Huygens' principle and diffraction phenomena for a monochromatic point source and diffraction by an aperture of simple form. Discussions focus on diffraction at infinity and at a finite distance, simplified expressions for the field, calculation of the path difference, diffraction by a rectangular aperture, narrow slit, and circular aperture, and distribution of luminous flux in the airy spot. The book then examines Fourier transformation and diffraction by several apertures. The manuscript takes a look at extended luminous sources and objects and diffraction phenomena in perfect optical instruments. Topics include diffraction gratings, phase contrast, apodization, filtering spatial frequencies, relation between the length of wave trains and the spectral width of the emitted radiations, successive wave trains emitted by an atom, and vibrations with different frequencies from a single atom. The manuscript also reviews diffraction phenomena in real optical instruments, including diffraction in the case of a spherical wave and diffraction spot in the presence of aberrations. The publication is a dependable reference for readers interested in diffraction phenomena.
Publisher: Elsevier
ISBN: 1483185729
Category : Science
Languages : en
Pages : 152
Book Description
Diffraction: Coherence in Optics presents a detailed account of the course on Fraunhofer diffraction phenomena, studied at the Faculty of Science in Paris. The publication first elaborates on Huygens' principle and diffraction phenomena for a monochromatic point source and diffraction by an aperture of simple form. Discussions focus on diffraction at infinity and at a finite distance, simplified expressions for the field, calculation of the path difference, diffraction by a rectangular aperture, narrow slit, and circular aperture, and distribution of luminous flux in the airy spot. The book then examines Fourier transformation and diffraction by several apertures. The manuscript takes a look at extended luminous sources and objects and diffraction phenomena in perfect optical instruments. Topics include diffraction gratings, phase contrast, apodization, filtering spatial frequencies, relation between the length of wave trains and the spectral width of the emitted radiations, successive wave trains emitted by an atom, and vibrations with different frequencies from a single atom. The manuscript also reviews diffraction phenomena in real optical instruments, including diffraction in the case of a spherical wave and diffraction spot in the presence of aberrations. The publication is a dependable reference for readers interested in diffraction phenomena.
Diffraction by Apetures Illuminated with Partially Coherent Light
Author: Robert A. Shore
Publisher:
ISBN:
Category : Diffraction
Languages : en
Pages : 16
Book Description
The intensity distribution in the Fraunhofer diffraction patterns of slit and circular apertures illuminated with partially coherent light is examined both theoretically and experimentally. It is shown that a detailed knowledge of the mutual coherence function across the diffracting apeture is required to describe fully the diffraction phenomena.
Publisher:
ISBN:
Category : Diffraction
Languages : en
Pages : 16
Book Description
The intensity distribution in the Fraunhofer diffraction patterns of slit and circular apertures illuminated with partially coherent light is examined both theoretically and experimentally. It is shown that a detailed knowledge of the mutual coherence function across the diffracting apeture is required to describe fully the diffraction phenomena.