Investigation of Photonic Crystal Based Optical Devices and Components for All Optical Switching

Abstract

newline Photonic crystals (PhCs) have created hope for entirely new possibilities in newlineoptics and photonics. Periodic modulation of refractive index in PhCs creates newlineforbidden wavelength region for propagation of optical waves which is called photonic newlineband gap (PBG). Knowledge of PBG can be exploited in designing PhC based optical newlinestructures (devices/components) which can function in desired manner to perform newlinepredetermined tasks, therefore, PhC based structures are being considered most suited newlinefor realizing all optical systems. Many efforts are being made over the globe to realize newlinepractically implementable and commercially viable all optical systems/devices. newlineIn this thesis, two dimensional photonic crystal devices have been designed and newlinesimulated to explore structures which can function in desired manner to perform newlinepredetermined tasks. The thesis is organized as below mentioned: newlineChapter 1 introduces history, concept, characteristics and dispersion diagram newlineof photonic crystals (PhCs). newlineIn chapter 2, two numerical methods are discussed, (1) plane wave expansion newline(PWE) method and (2) finite difference time domain (FDTD) method. PWE method newlinecalculates the Eigen frequencies and dispersion properties of PhC by numerically newlinesolving the Maxwell s equations in frequency domain, whereas the FDTD method newlinesolves Maxwell s curl equations in the time domain using finite difference newlineapproximation. newlineChapter 3 proposes a structure based on nonlinear photonic crystal ring newlineresonant cavity (NPCRRC) that can mimic NOT and AND gates. The proposed NOT newlineand AND gates are better in terms of operating power and ON/OFF contrast newlinecompared to earlier reported work. These features are very much desired and essential newlinefor practicability for any all optical device.