Ultra-small modulator and demodulator for 10 Gb/s differential phase-shift-keying (DPSK), using silicon-based microrings, are proposed. A single-waveguide microring modulator with over-coupling between ring and waveguide generates a DPSK signal, while a double-waveguide microring filter enables balanced DPSK detection. These modulator and demodulator are characterized. A trade-off between patte...

We demonstrate that high transmission through sharp bends in photonic crystal waveguides can be described by a simple model of the Fano resonance where the waveguide bend plays a role of a specific localized defect.We derive effective discrete equations for two types of the waveguide bends in two-dimensional photonic crystals and obtain exact analytical solutions for the resonant transmission a...

The concept of adiabatic mode transformation between silicon waveguide and surface plasmon-polariton modes in subwavelength metal-dielectric slots is investigated. The mode transformer consists of a modulated-index slot region, which is bound by two metal slabs. Using the design scheme, we will show that the optical dispersion of a modulated-index metal slot waveguide can be engineered well abo...

This study presents the design of a compact Radio Frequency Identification chipless tag, with reduced size, important quality factor and improved results. The proposed prototype is based on Substrate Integrated Waveguide technology using the Half-Mode Substrate Integrated Waveguide technique to reduce the tag size by the half and preserve the same response. Further, the operating frequency band...

We investigate the loss mechanism in three-moded multimode-interference couplers that are the building blocks of a compact and low-loss waveguide crossing structure. Broadband silicon waveguide crossing arrays with <0.01  dB insertion loss per crossing are proposed using cascaded multimode-interference couplers, where lateral subwavelength nanostructures are used to reduce the insertions loss. ...

We present predicted relative scattering losses from sidewall roughness in a strip waveguide compared to an identical waveguide surrounded by a photonic crystal with a complete or incomplete gap in both 2d and 3d. To do so, we develop a new semi-analytical extension of the classic “volume-current method” (Green’s functions with a Born approximation), correcting a longstanding limitation of such...

A generalized equivalent circuit model for waveguide transverse slots is proposed for the efficient analysis of waveguide transitions and waveguide slot antennas and slot-excited antennas. The transverse slots on the broad and end waveguide walls analyzed in this paper are decomposed into three structures: two apertures and an auxiliary waveguide section. The slot aperture in the host waveguide...