摘要:

A proof is given of the necessity and sufficiency of conditions on a spatial filtering system for imaging of thin phase objects.

ISSN:0030-3909    

DOI:10.1080/713820154

出版商:Taylor & Francis Group    

年代:1980

数据来源: Taylor

ISSN:0030-3909    

DOI:10.1080/713820156

出版商:Taylor & Francis Group    

年代:1980

数据来源: Taylor

ISSN:0030-3909    

DOI:10.1080/713820153

出版商:Taylor & Francis Group    

年代:1980

数据来源: Taylor

ISSN:0030-3909    

DOI:10.1080/713820158

出版商:Taylor & Francis Group    

年代:1980

数据来源: Taylor

ISSN:0030-3909    

DOI:10.1080/713820161

出版商:Taylor & Francis Group    

年代:1980

数据来源: Taylor

ISSN:0030-3909    

DOI:10.1080/713820159

出版商:Taylor & Francis Group    

年代:1980

数据来源: Taylor

摘要:

The numerical study of the transmission of laser pulses through a two-photon absorber is given for Fourier-limited and chaotic pulses. The light statistics are investigated through a calculation of the second-order correlation functiong(2)which is shown to be very sensitive to the experimental conditions.

ISSN:0030-3909    

DOI:10.1080/713820151

出版商:Taylor & Francis Group    

年代:1980

数据来源: Taylor

摘要:

A T.V. type of analogue image processor using a scan-converting storage tube is described. In this processor, the pictures pre-processed by video delay lines and multipliers in an image-serial and aperture-parallel manner are superimposed successively on the target surface of the tube in an image-parallel and aperture-serial manner. It is shown theoretically and experimentally that when the image-serial and aperture-parallel pre-processing is applied to the well-separated groups of subdivided aperture-weights, the above processing method becomes very effective. Some experimental results of restoration of defocused images are presented, showing that the quality of restored images is comparable with those obtained by digital computer.

ISSN:0030-3909    

DOI:10.1080/713820148

出版商:Taylor & Francis Group    

年代:1980

数据来源: Taylor

摘要:

The present paper presents a simple and fast method for solving the phase problem in scattering determinations. After defining the problem in the introduction, the paper outlines, in § 2, the main conventional approaches to solving the phase problem, which is due to the presence of complex zeros of the scattered field in the space of measurement. IfNsuch zeros are present, the ambiguity in solving the inverse scattering problem in 2N. Section 3 offers the mathematical foundations of the proposed new method. It discusses the properties of the distributions of zeros and in particular the way in which they encode the information in the object space. Using these properties as a basis, § 4 puts forward a method for zero location, which involves two conventional scattering measurements, withouta prioriinformation. The main advantage of the procedure consists of reducing the number of computations required for determining possible solutions from 2Nto 2N, by using an iterative procedure.

ISSN:0030-3909    

DOI:10.1080/713820149

出版商:Taylor & Francis Group    

年代:1980

数据来源: Taylor

摘要:

An experimental and theoretical study on atmospheric laser transmission is given. An in general continuously operating transmissometer measured the attenuation at 10·6 and 0·63 μm over several weeks. Extinction effects at different meteorological conditions, including rain, snow-fall, fog and haze, from measurements and calculations, are presented.

ISSN:0030-3909    

DOI:10.1080/713820157

出版商:Taylor & Francis Group    

年代:1980

数据来源: Taylor