Abstract

We propose, for the first time to our knowledge, a new feedback fabrication technique for rugate filters with sinusoidal refractive index distribution. The technique uses an in situ optical monitoring system, in contrast to conventional techniques for rugate filters that are based on time control, which is generally unsuitable for accurate fabrication of a continuous index distribution. We employed a-SiO_x:H thin film as the material for the rugate filters because its refractive index can be successively controlled. Using the proposed technique and material, we fabricated near-infrared rugate minus filters having multiple and continuous refractive index distributions. The experimental and calculated spectra were well correlated as a result of applying the proposed feedback fabrication technique.

© 2006 Optical Society of America

a-Si:H/SiO₂ multilayer films fabricated by radio-frequency magnetron sputtering for optical filters

Hidehiko Yoda, Kazuo Shiraishi, Yuji Hiratani, and Osamu Hanaizumi
Appl. Opt. 43(17) 3548-3554 (2004)

Application of optical broadband monitoring to quasi-rugate filters by ion-beam sputtering

Marc Lappschies, Björn Görtz, and Detlev Ristau
Appl. Opt. 45(7) 1502-1506 (2006)

Rugate filters fabricated from dense and porous magnetron sputtered WO₃ films

Jean Desforges, Corentin Cheminot, Nicolas Laville, and Georges Bader
Appl. Opt. 53(4) A110-A113 (2014)

Oxidation of evaporated porous silicon rugate filters

Kevin Robbie, Yan Cui, Chelsea Elliott, and Kate Kaminska
Appl. Opt. 45(32) 8298-8303 (2006)

Near infrared rugate filter fabrication by ion beam assisted deposition of Si₍₁₋X₎NX films

Edward P. Donovan, D. Van Vechten, Alan D. F. Kahn, Carmine A. Carosella, and Graham K. Hubler
Appl. Opt. 28(14) 2940-2944 (1989)