Photonic bandgap materials and structures by sol-gel processing

• Type: Article in International Scientific Journal
• Date: 2003

Authors

Almeida, RM (Author) Other; Rodrigues, AS (Author) FCUP

Journal

Title: Journal of Non-Crystalline Solids

Vol. 326

Pages: 405-409

ISSN: 0022-3093

Publisher: Elsevier

Indexing

ISI Web of Knowledge - 64 Citations

Scopus - 70 Citations

Scientific classification

FOS: Engineering and technology > Materials engineering

Other information

Authenticus ID: P-000-F0T

DOI: 10.1016/s0022-3093(03)00447-2

Abstract (EN): The sol-gel method is an inexpensive and flexible liquid phase processing technique that is suitable for the fabrication of 1-D photonic bandgap structures, such as multilayer dielectric mirrors. In the present work, we started by preparing highly reflecting quarter-wave multilayer stacks, composed of alternating films of high refractive index material (TiO2) and low refractive index material (SiO2), possessing well-defined stop bands. For example, for a 11-layer stack, a stop band was obtained with more than 96% reflectance (at near-normal incidence) between similar to600 and 700 nm, with a gap to mid-gap ratio Deltalambda/lambda(max) = 15.4%. Fabry-Perot micro-cavities, containing high or low index defects within the quarter-wave stack, were also prepared and tested. Such structures were optimized with the help of suitable modeling, using transfer matrix techniques. Various experimental techniques were used to characterize these multilayers, including ellipsometry, visible spectroscopy, X-ray diffraction and atomic force microscopy.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 5