In recent years, there has been more research on the use of photonic crystals PCs in the field of detection. The application of these materials as gas sensors seems very promising, because of their miniaturization and high spectral sensitivities. The aim of this work is to contribute to the design and study of a resonant microsystem based on one-dimensional photonic crystals for applications such as optical devices with high quality factor for detecting and measuring the concentration of gas in the air. Indeed, we have proposed a gas monitoring structure. This nanosystem is formed by an alternating stack of silicon Si layers and air with a resonant nanocavity in the middle. The numerical results show that the resonance peak that appears on the Photonic Band Gap (PBG) is caused by the creation of the nanocavity within the periodic 1D structure. This resonance peak can be used as a reference for real-time detection and environmental monitoring. In addition, we theoretically studied the relevance of these photonic systems and analyzed the effect of the intrinsic and extrinsic parameters of this device on the detection performance. We have also tried to improve the performance of such a device for the effect study of the inclination variation of the radiation incidence source on the selectivity of the detector.

No abstract

Nonlinear effect on optical properties of one-dimensional photonic crystal (1D-PC) of the type (HL) n (LH) m (LLHH) k was investigated. It is an asymmetric hybrid Fabry-Perot resonator type of 1DPC structure which is composed of linear (H layers) and nonlinear (L layers) materials. The linear and nonlinear transmission spectra are graphically illustrated using a numerical approach based on the Transfer Matrix Method (TMM). Results show the appearance of a Perfect Transmission Peak (PTP) in the photonic band gap which makes the structure constitute a monochromatic filter. By analyzing this PTP it is shown that the Full-Width at Half-Maximum (FWHM) depends not only on the number of symmetry layers of the studied 1D-PC but also on the refractive index of the nonlinear layers. The change of the refractive index (Kerr effect) causes a dynamically shift in the band gap including the resonance peak. As a result, such a structure has the potential to be used for designing optical filters and nonlinear optical devices.