We report an experimental study of porous silicon-based rugate filters. Possible optimisations that can improve different features of the filters are investigated. We demonstrate sidelobe attenuation by means of half-apodization of the structures with a sinusoidal window. Reduction of interference ripples are experimentally observed through the insertion of index-matching layers on the boundaries of the structure. The superposition of two different designs to obtain a multi-stop-band filter is also demonstrated. We show the possibility of controlling the bandwidth of the stop-bands by varying the index contrast. All the results are discussed and compared with numerical calculations. © 2005 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
|Titolo:||Fabrication and optimization of rugate filters based on porous silicon|
|Data di pubblicazione:||2005|
|Appare nelle tipologie:||4.1 Contributo Atti Congressi/Articoli in extenso|