Abstract:
This thesis is dedicated to the study and design of new structures for optical detection.
Indeed, the development of these optical devices has a growing and particular interest,
particularly for targeting and identifying biological species. For this purpose, the photonic
crystal-based components (CPs) have been widely exploited in the field of bio-detection.
Silicon is an ideal candidate designated as a support material for the realization of these
devices. In this context, new coupling techniques between waveguide and optical cavity based
on planar photonic crystals, made on a silicon-on-insulator (SOI) substrate, have been
developed. To do this, we are modeling these bio detectors, optimizing their key parameters
such as the quality factor and sensitivity to the optical index of the external environment,
using commercial software Fullwave and Crystalwave that exploit the finite difference
method in the two-dimensional time domain (FDTD-2D). We first studied the parallel
coupling between a resonant cavity and a waveguide (W1) for application to the detection of
DNA biomolecules. The originality of this study is to consider several sensors on a single
platform, and to demonstrate that each sensor could detect a target independently and without
interaction with others, without losses, and this, by acting on the parameters influencing the
essential characteristics, we note a high sensitivity and a low limit of detection. As for the
second geometry studied, it consists of another coupling path, the latter comprises two
sections of guides W1 between which has been arranged a ring cavity. We have also
optimized the different structural parameters for this configuration, in order to improve the
sensitivity and the quality factor in order to obtain another type of high-performance sensor,
namely the temperature sensor. For this, we consider the evolution of the sensitivity as a
function of the change in the temperature of the water, convincing results were noted.
