摘要:

Computer simulation of thin-film multilayer production has shown that the effects of errors in the layers on the performance of complete coatings depends strongly on the particular monitoring process used. Deposition of dielectric quarter-wave multilayers is usually controlled by a method which involves the detection of the maxima and minima of transmission for the centre wavelength of the filter, the turning value method, and we know that this technique profits from an exceptionally efficient error compensation. The true tolerances in stack production are much larger than we would calculate neglecting this compensation. However, the analysis of experimental results shows that we must consider other effects which have so far been neglected in the computer simulation and which affect the monitoring process enough to prevent the fabrication of interference filters with very narrow transmission bands. Here we describe how the computer simulation is modified to take account of the influence of temperature changes during filter manufacture. First, it is necessary, for each material used, to determine the dilatation coefficients of both refractive index and thickness; they may be deduced from measurements of shifts with temperature of the centre wavelength of narrow-band filters of two different designs. Then, as a first approximation, we assume in the simulation a gradual temperature change which is always proportional to the deposited thickness and which reaches a total of 60°C for the complete filter. The calculations show that the effects of such a temperature change cannot be neglected even if the actual monitoring is perfect, that is if the deposition is always terminated exactly at a turning value of transmittance. The optical characteristics of very narrow-band filters, and especially of double half-wave filters, are seriously degraded. If, in addition, errors in determination of the turning values are included, then the effects are considerably worse. This can explain why it is so difficult to make filters with passband width less than 8 Å. The results of this study can be used to choose optimal conditions for the production of narrow-band filters.

ISSN:0030-3909    

DOI:10.1080/713818867

出版商:Taylor & Francis Group    

年代:1974

数据来源: Taylor

摘要:

Pour diminuer la bande passante de filtres interférentiels, nous avons utilisé des empilements type double onde dont une couche est constituée par une lame de mylar. L'étude théorique et expérimentale de ces filtres en fonction de l'angle d'incidence nous a permis de déterminer l'ordre de grandeur et la distribution des erreurs de réalisation. Le substrat étant élastique et biréfringent, nous avons montré qu'il était possible d'effectuer un léger déplacement de la longueur d'onde de centrage du filtre.

ISSN:0030-3909    

DOI:10.1080/713818866

出版商:Taylor & Francis Group    

年代:1974

数据来源: Taylor

摘要:

The spectral behaviour of the reflected and transmitted light from a dielectric multilayer film at an oblique angle of incidence is discussed. These spectra are different for both states of polarizationspandseven when the incoming light is unpolarized. The difference between both spectra of the two states of polarization is regarded as the polarization effect. This effect is investigated for three cases: all dielectric Fabry-Perot interference filters (ADI), Long and Short-wave Pass Filters (LWPF and SWPF) and multilayer antireflection coatings (AR). The conditions for avoiding or reducing these polarization effects in multilayer dielectric thin films of the above-mentioned cases are found and applied. Typical designs and calculated spectra are given and discussed.

ISSN:0030-3909    

DOI:10.1080/713818869

出版商:Taylor & Francis Group    

年代:1974

数据来源: Taylor

摘要:

Polychromatic or white-light OTF is put forward as a criterion of image quality for systems under actual working conditions. The formulae necessary to extend from the monochromatic to the polychromatic OTF are developed for the axial case. A computer programme has been developed and calculated results are compared with measurements.

ISSN:0030-3909    

DOI:10.1080/713818864

出版商:Taylor & Francis Group    

年代:1974

数据来源: Taylor

ISSN:0030-3909    

DOI:10.1080/713818870

出版商:Taylor & Francis Group    

年代:1974

数据来源: Taylor

ISSN:0030-3909    

DOI:10.1080/713818868

出版商:Taylor & Francis Group    

年代:1974

数据来源: Taylor

ISSN:0030-3909    

DOI:10.1080/713818871

出版商:Taylor & Francis Group    

年代:1974

数据来源: Taylor