Modelling of photonic wire Bragg Gratings

Some important properties of photonic wire Bragg grating structures have been investigate. The design, obtained as a generalisation of the full-width gap grating, has been modelled using 3D finite-difference time-domain simulations. Different types of stop-band have been observed. The impact of the grating geometry on the lowest order (longest wavelength) stop-band has been investigated - and has identified deeply indented configurations where reduction of the stop-bandwidth and of the reflectivity occurred. Our computational results have been substantially validated by an experimental demonstration of the fundamental stop-band of photonic wire Bragg gratings fabricated on silicon-on-insulator material. The accuracy of two distinct 2D computational models based on the effective index method has also been studied - because of their inherently much greater rapidity and consequent utility for approximate initial designs. A 2D plan-view model has been found to reproduce a large part of the essential features of the spectral response of full 3D models

A photonic nano-Bragg grating device integrated with microfluidic channels for bio-sensing applications

A photonic wire Bragg grating structure, integrated with fluidic channels and reservoirs for fluid sensing based on refractive index changes, has been designed using 3-D Finite Domain Time Difference (FDTD) method and fabricated using electron beam lithography and reactive ion etching on an Silicon-on-Insulator (SOI) material. A scheme is developed where a Polydimethylsiloxane (PDMS) microfluidic chip is integrated with the SOI photonic chip via a reversible active sealing method. The highest sensitivity (Delta n/Delta lambda) of the device is estimated to be 5.5 x 10(-3) nm(-1) and the volume of the sensing region is approximately 2 mu m(3). This device could be a potential candidate for lab-on-a-chip devices for bio-sensing applications

Integration of a 2-D photonic crystal superprism with 1-D photonic crystal microcavity filters for high channel selectivity

A 2-D photonic crystal superprism-filter device for demultiplexing applications has been designed using Plane Wave Expansion and 2-D Finite Difference Time Domain methods. High channel selectivity with peak transmission linewidths of 15 nm is achievable. © 2005 IEEE