NUMERICAL ANALYSIS OF PHOTONIC CRYSTAL WAVEGUIDE

During the last decade, a major research interest is focused on optical sensors for chemical and biosensing application relaying on refractive index (RI) measurements. Among this class of optical sensors the waveguides confined inside of photonic crystals are of high interest. The application of such RI optical sensors is interesting for both gaseous and aqueous samples and includes measurement of parameters like temperature, humidity, chemical composition and biosensing. The improvement of designing RI optical sensors implies analysis of electromagnetic wave propagation into photonic crystals which is strongly influenced by the internal geometry and by the materials of the photonic crystals. Electromagnetic wave propagation into a 2D photonic crystal consisting of an array of circular or elliptical pillars made of dielectric materials placed into air or water is investigated. Some pillars are removed to make a waveguide with a 90 bend. The laser wavelengths of 632.8, 1064 and 1554 nm are considered. The pillars of the photonic crystal are made of GaAs, GaP or GLS. The electromagnetic wave propagation is analysed using the FEM and perfectly matched layers have been employed as boundary conditions. Comprehensive numerical calculations have been performed considering several transverse dimensions circular or elliptical pillar geometries.