Pulse propagation in adiabatically coupled photonic crystal coupled cavity waveguides

Abstract

A rigorous analysis of pulse propagation in planar photonic crystal (PhC) coupled cavity waveguides (CCWs) of finite length is reported. Conventional PhC waveguides, formed by a single line defect, are used at both interfaces of the CCW. An adiabatic taper based on progressively varying the radii of the spacing defects between cavities is used to achieve flat transmission bands with respect to the butt coupling case. The influence on the main parameters of the propagated pulse such as group delay, full width at half maximum and pulse attenuation are investigated for both the adiabatic and butt coupling cases. Furthermore, the Fabry-Perot formula has been used for modeling the pulse propagation along the CCW of finite length, which permits to analyze a large range of parameters avoiding the huge computation time requirements of finite-difference time-domain simulations.

Optimization of Optical Delay Lines based on Photonic Crystal Coupled Cavity Waveguides

“…This CCW is coupled to line defect waveguide (LDWG) at either ends to facilitate integration with external devices. Different schemes of coupling between CCW and LDWG have been reported earlier [8]- [9]. After analyzing these schemes, we observed that for our waveguide design, the overall power transmission was maximum when two extra air holes were placed at these interfaces probably due to the effect of adiabatic transition.…”

Experimental demonstration of adiabatic coupling into SOI photonic crystal coupled-cavity waveguides

“…The undesired resonance peaks are eliminated by the introduction of the adiabatic taper in the structure. The underlying physics of the taper is an adiabatic matching of the dispersion relations of the SLWG and the CCW [3].…”

“…An adiabatic coupling technique between single-line-defect waveguides (SLWGs) and CCWs was recently proposed [2]. Furthermore, their dynamic performance by analyzing the transmission of ultrashort pulses through the structure was also investigated [3]. The coupling technique is based on gradually varying the radii of the spacing defects between cavities, as it can be seen in Fig.…”

Experimental results on adiabatic coupling into SOI photonic Crystal coupled-cavity waveguides

“…An adiabatic coupling technique between single-line defect waveguides (SLWGs) and CCWs was recently proposed [5]. Furthermore, the dynamic performance was also investigated by analyzing the transmission of ultrashort pulses through the structure [6]. The coupling technique is based on gradually varying the radii of the spacing defects between cavities in order to match the SLWG and CCW modes.…”