Wüest M. 51 Wykes M. 82 Yamaguchi M. 17 Ybarra G. 129 Yubero F ...

JUNE 26 MONDAY MORNING
ETCHC-MoM-OR.2 COMPUTER DESIGN OF OPTICAL COATINGS IN SYSTEMS
WITH CONTINUOUSLY VARYING REFRACTIVE INDEX. J.F. Trigo. Departamento de
Energía, CIEMAT, Avda. Complutense 22, E-28040 Madrid, Spain. I. Preda, S. Palacín, A. Gutiérrez
and L. Soriano. Departamento de Física Aplicada C-XII, Universidad Autónoma de Madrid, Cantoblanco
E-28049 Madrid, Spain
A simple computerized method for the calculation and refinement of a multilayer discrete optical design
has been used to test the accuracy and stability of the given solution with continuously varying
refractive index systems as compared with usual high-low (HL) bilayer systems.
Motivated for the study of nanostructured mixed materials, which results in a controlled variation of
the index of refraction, a code for multilayer Reflectance-Transmittance calculation has been modified
to treat the problem of continuously varying refractive index. An example of sinusoidal variation
has been studied and compared with discrete HL multilayer to produce a step filter. Also the stability
of the filter Transmittance against a random dispersion of the layers thickness has been compared.
The conclusion of the comparison was that the bilayered model was better in producing sharp step
filters but this performance was rapidly destroyed by a random dispersion up to a 20% of the layers
thickness whereas the sinusoidal continuous variation of the refractive index filter remained stable in
the same condition. This indicates that the design calculated for these continuous systems would be
more easily produced and reproduced in batch industrial processes.
On the other hand, the calculation and refinement of the continuous optical coating is much more
time consuming with our method so considerable effort has been done to improve the code in this
sense.
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