Showing papers by "Rajib Chakraborty published in 2013"
TL;DR: In this article, a 1D binary periodic structure with defect was analyzed using Transfer Matrix Method (TM) and FDTD simulation, and it was shown that the field is localised within the defect for the passband frequency.
28 citations
TL;DR: In this article, an effective index based matrix method was used to analyze high-index contrast slab and slot optical waveguides, and the results were compared with results obtained from numerical techniques like finite element method, finite-difference time-domain, and beam propagation method.
Abstract: High-index contrast slab and slot optical waveguides have a high index variation both along the lateral and vertical interfaces and are usually analyzed numerically, requiring large computer memory and time. In this article, their analysis is done semianalytically using an effective-index based matrix method. This method, which is computationally very fast, was earlier used successfully for low-index profile waveguide structures only and is now suitably modified for use in high-index contrast structures. The electric field profile of the waveguide structures is plotted and the effective refractive index at different wavelengths is calculated. The results are compared with results obtained from numerical techniques like finite element method, finite-difference time-domain, and beam propagation method and they match very well. The dependence of their different optical characteristics with the waveguide parameters is also studied. These studies will help in obtaining improved sensitivity of slot waveguides for sensing applications.
12 citations
TL;DR: In this article, an interferometric technique to measure the phase variation of the film surface has been proposed, which is comparable with the surface quality as obtained from AFM images.
4 citations
TL;DR: In this paper, a Mach-Zehnder interferometric setup is used and the voltage required for phase reversal of the fringe pattern is noted for single domain and domain inverted sample.
Abstract: Change in the value of half-wave voltage of ${\rm LiNbO}_{3}$ ( $z$ -cut) before and after high electric field domain inversion at room temperature has been reported. For verification, a Mach–Zehnder interferometric setup is used and the voltage required for phase reversal of the fringe pattern is noted for single domain and domain inverted sample. The technique of the used domain inversion process is discussed and confirmation of the domain inversion is also done. As the half-wave voltage decreases after domain inversion, it may be assumed that the overall electro-optic property of ${\rm LiNbO}_{3}$ has been enhanced. This might possibly been caused by the internal field compensating the spontaneous polarization of the crystal.
4 citations
TL;DR: In this article, high-index contrast slot waveguides whose field suffers strong discontinuities at its interface are analyzed semi-analytically using Transfer Matrix along with Effective Index Method.
Abstract: High-index contrast slot waveguides whose field suffers strong discontinuities at its interface are analyzed semi-analytically using Transfer Matrix along with Effective Index Method. The results are comparable with results obtained from different numerical techniques.