Optimization of bandpass optical filters based on TiO2nanolayers

Synthesis of high-order bandpass filters based on coupled-resonator optical waveguides (CROWs).

We present a filter design formalism for the synthesis of coupled-resonator optical waveguide (CROW) filters. This formalism leads to expressions and a methodology for deriving the coupling coefficients of CROWs for the desired filter responses and is based on coupled-mode theory as well as the recursive properties of the coupling matrix. The coupling coefficients are universal and can be appli...

Highly selective terahertz bandpass filters based on trapped mode excitation.

We present two types of metamaterial-based spectral bandpass filters for the terahertz (THz) frequency range. The metamaterials are specifically designed to operate for waves at normal incidence and to be independent of the field polarization. The functional structures are embedded in films of benzocyclobutene (BCB) resulting in large-area, free-standing and flexible membranes with low intrinsi...

Ultra-narrow bandpass filters based on volume Bragg grating technologies

Free space optical communication between movable platforms, especially communication with non-cooperative targets, requires detecting low intensity signals in conditions of multiple sources of contaminating signals. In this paper, we review recent achievements in ultra-narrow bandpass filters based on volume Bragg gratings (VBGs) recorded in the bulk of photo-thermo-refractive glass. The new ty...

Microelectromechanical bandpass filters based on cyclic coupling architectures

Quality Factor Enhancement of Optical Channel Drop Filters Based on Photonic Crystal Ring Resonators

In this paper, a channel drop ring resonator filter based on two dimensional photonic crystal is proposed which is suitable for all optical communication systems. The multilayer of silicon rods in the center of resonant ring enables one to adjust resonant wavelength of the ring and enhance power coupling efficiency between ring and waveguide. Refractive index and radius of multilayer rods insid...