ISSN:0030-3909    

DOI:10.1080/713818487

出版商:Taylor & Francis Group    

年代:1971

数据来源: Taylor

摘要:

A double refracting interference microscope, which is capable of giving uniform and fringe interference field with both the amount and direction of image duplication continuously variable, has been developed. A combination of two simultaneously acting birefringent prisms, separated by a half-wave plate and inserted between a polarizer and analyser, is used. One of these prisms, of the Nomarski type, is incorporated in objectives and is rotatable round the objective axis. Rotation of this prism enables the amount and direction of image duplication to be changed. The other prism, of the Nomarski or Wollaston type, is placed in the microscope tube and can be slid in a direction perpendicular to the microscope axis. This translation serves for shifting the phase of interfering light waves, for measuring the optical path difference between an object under investigation and its surrounding medium. As a source of coherent light a slit diaphragm located in the front focal plane of a condenser is used. Both the slit diaphragm and half-wave plate, as well as the polarizer, are rotatable around the microscope axis when the objective birefringent prism is turned. Advantages and application possibilities of this system are discussed.

ISSN:0030-3909    

DOI:10.1080/713818490

出版商:Taylor & Francis Group    

年代:1971

数据来源: Taylor

摘要:

In the case of a periodic object, the wave amplitude in every point of a Fresnel diffraction pattern may be obtained from the values of the wave amplitude at a finite number of points in the object plane. This results is applied to the case of pure phase objects. A simple condition on the object structure is derived, which would allow the object phase distribution to be determined directly from a measured intensity profile for a certain defocusing distance.

ISSN:0030-3909    

DOI:10.1080/713818491

出版商:Taylor & Francis Group    

年代:1971

数据来源: Taylor

摘要:

The influence of random wavefront errors on the transfer function and point spread function of an optical system is studied theoretically. The stochastic part of the aberration function is assumed to be Gaussian and spatially stationary (although the requirement of stationarity is relaxed in § 5). The stochastic transformation from wavefront to transfer function is non-linear. The consequences of this non-linear transformation are two-fold: first, the statistics of the transfer function are non-Gaussian, second, the transfer function is non-stationary. (The same statements hold for the point spread function.) Therefore the characterization of these processes requires an infinite number of averaged products (moments), not just the first two if the processes were Gaussian. These averaged products are obtained in the form of multiple integrals involving the characteristic function of the wavefront and are suitable for calculation on a high speed computer. Some numerical results for the mean of both processes are presented.

ISSN:0030-3909    

DOI:10.1080/713818488

出版商:Taylor & Francis Group    

年代:1971

数据来源: Taylor

摘要:

Goldhydrosole mit verschieden grossen Teilchen wurden auf ihr optisches Verhalten hin im sichtbaren Gebiet überprüft, und die Grösse 2nkder Kolloide wurde mit aus dem Massivmaterial gewonnenen Werten verglichen. Unter Annahme einer der Teilchenzahl entsprechenden Auflockerung liessen sich die bei den Hydrosolen auftretenden Maxima von 2 nk zwanglos erklären. Zwischen dem Auflockerungsfaktor δ und der Teilchenzahldichte N wurde eine Funktion aufgestellt, die bei bekanntem δ eine Berechnung der Teilchenzahldichte — bzw. bei zusätzlich bekannter Konzentration eine Berechnung des Metallvolumens — aus dem massiven Material gestattet.

ISSN:0030-3909    

DOI:10.1080/713818486

出版商:Taylor & Francis Group    

年代:1971

数据来源: Taylor

ISSN:0030-3909    

DOI:10.1080/713818489

出版商:Taylor & Francis Group    

年代:1971

数据来源: Taylor