摘要:

The established methods of interferometrically testing lens surfaces by comparison with a master surface are summarized, and the difficulties which arise in the case of steeply curved surfaces are explained. An instrument is described which enables highly curved spherical surfaces of numerical aperture up to 0.95 to be tested interferometrically at normal incidence. The method, which is non-contacting, allows the fringe pattern to be adjusted to the preferred form of straight line fringes, and obviates the risk of damage through scratching. Further, each master surface may be used with a variety of test surfaces of different radii of curvature. It is possible also to use the instrument in a subsidiary role as a relative spherometer accurate to about one micron with respect to the master surface, and as a Fizeau interferometer for the testing of less steeply curved surfaces and optical flats.

ISSN:0030-3909    

DOI:10.1080/713818167

出版商:Taylor & Francis Group    

年代:1969

数据来源: Taylor

摘要:

The depth of modulation of the interference pattern in a two-beam interferometer is considered for systems in which the superposed wavefronts are nominally parallel. The effects are considered, for laser illumination with a Gaussian distribution, of imperfect superposition and parallelism of the wavefronts.

ISSN:0030-3909    

DOI:10.1080/713818174

出版商:Taylor & Francis Group    

年代:1969

数据来源: Taylor

摘要:

The effect of random and sinusoidal errors, usually appearing on the Lummer-Gehrcke plates during the polishing process, has been investigated. Analytical relations have been obtained for the intensity distribution in the fringe pattern in the presence of such errors on the plate. The results have been utilized to assess the permissible limits of the errors on the surface of the plates.

ISSN:0030-3909    

DOI:10.1080/713818163

出版商:Taylor & Francis Group    

年代:1969

数据来源: Taylor

摘要:

The method used by Boyce [1] has been used to examine the accuracy of fixation of the centre of a disc target as a function of the angle subtended by the disc at the eye. Angular diameters from 19′–240′ were used. The R.M.S. deviation of the direction of the visual axis from its mean direction increases by less than a factor of two between the extreme sizes of the target. There is an unexplained reduction in accuracy of fixation when the diameter of the target is about equal to the diameter of the fovea. Experiments have also been carried out on the accuracy of fixation of the centre of two small dots separated either vertically or horizontally at function of distance between the dots. The accuracy of fixation for these targets is unexpectedly good.

ISSN:0030-3909    

DOI:10.1080/713818162

出版商:Taylor & Francis Group    

年代:1969

数据来源: Taylor

ISSN:0030-3909    

DOI:10.1080/713818173

出版商:Taylor & Francis Group    

年代:1969

数据来源: Taylor

摘要:

Diffraction images of coherently illuminated objects in the presence of aberrations are studied; in particular the images of edges, discs and bars are obtained for both amplitude and phase objects. Representative numerical calculations are included.

ISSN:0030-3909    

DOI:10.1080/713818159

出版商:Taylor & Francis Group    

年代:1969

数据来源: Taylor

摘要:

In this paper the quantum-mechanical evaluation of the rotatory dispersion of crystals is described. This evaluation follows from the model of coupled oscillators with respect to the damping. Also, the generalized equation of the rotatory power of crystals is obtained, from which all the most important formulae already derived follow as special cases.

ISSN:0030-3909    

DOI:10.1080/713818170

出版商:Taylor & Francis Group    

年代:1969

数据来源: Taylor

摘要:

Nous étudions la dispersion anomale de l'indice de réfraction des corps absorbants dans les domaines visibles et proche ultra-violet. Nous avons pour cela mis au point un réfractomètre photoélectrique automatique de grande sensibilité (détection d'une variation d'indice de 2 × 10-6). Les mesures s'effectuent en observant les modifications de la polarisation de la lumière réfléchie par le milieu considéré. Si l'indice d'extinction de ce dernier reste inférieur à 0,15, une relation de proportionnalité lie la variation d'azimut de la vibration réfléchie à la variation d'indice, qu'il est alors possible d'enregistrer automatiquement. Cette méthode permet, par ailleurs, de s'affranchir de la dispersion d'indice dûe aux bandes d'absorption lointaines de l'échantillon et de n'observer de ce fait que la dispersion anomale liée aux bandes d'absorption considérées. Nous présentons les résultats expérimentaux relatifs à FeCN6K3, K2Cr2O7, ErCl3. Un tel appareil, grâce à sa large gamme de mesures (Δnde 10-6à 10-1) et à sa grande sensibilité, permet l'étude des solutions et des solides dopés avec une précision suffisante pour examiner de façon critique les relations liant la dispersion de l'indice à l'absorption. Soulignons enfin que ces deux grandeurs sont mesurées sur le même échantillon et non sur des échantillons de concentration différente.

ISSN:0030-3909    

DOI:10.1080/713818168

出版商:Taylor & Francis Group    

年代:1969

数据来源: Taylor

ISSN:0030-3909    

DOI:10.1080/713818166

出版商:Taylor & Francis Group    

年代:1969

数据来源: Taylor

ISSN:0030-3909    

DOI:10.1080/713818169

出版商:Taylor & Francis Group    

年代:1969

数据来源: Taylor