The Transmission Properties of One-Dimensional Photonic Crystals with Gradient Materials

Abstract

In this paper, we studied the transmission properties, including photonic band gap (PBG) and defect mode properties, of one-dimensional photonic crystals (1D PCs) consisting of gradient materials. When keeping the average refractive index of the gradient materials in the 1D gradient-material PCs (1D GPCs) the same as the index of the corresponding normal materials in the 1D normal-material PCs (1D NPCs), by transfer matrix method, we found that the complete 1D GPCs with high-index gradient materials benefit to achieve larger omni-PBG than that in 1D NPCs. In our high-index gradient material case, for TE(TM) wave, the optimal omni-PBGs in 1D GPCs with first- and second-order gradient materials are 38.6% (50.2%) and 15.9% (22.3%) larger than that in 1D NPCs; while for the optimal relative bandwidths of omni-PBG, the corresponding promotions are 41.1% (52.3%) and 16.1% (22.6%), respectively. In addition, when defective 1D GPCs have gradient-material defect, the position of defect modes can be adjusted by selecting proper parameters of the gradient materials. These types of research are useful for designing wide PBG devices and tunable narrow-band filters which have potential application in optical communication.

Optimal design of multilayer optical thin film structure for smart energy saving applications using needle optimization approach

“…The mismatch between the coating materials and the surrounding medium causes ripples to appear in the pass band and the limited stop band range depends on the ratio of the refractive indices of the two optical materials used to construct the multilayer coating; a high ratio of refractive indices gives the widest PBG [26][27][28]. Because of their low insertion loss, good temperature stability and low cost, the edge filters are widely used in multimedia color projection displays, intelligent optical networks, optical fiber communication systems, and energy efficient smart windows [29][30][31][32][33][34][35][36][37][38]. This paper presents an approach that uses characteristic matrix and needle optimization as a synthesis technique to design an optimal SWP edge filter for the visible-near infrared (IR) region (400-1100 nm) [30][31][32][33].…”

High-performance biosensors based on angular plasmonic of a multilayer design: new materials for enhancing sensitivity of one-dimensional designs

“…[24][25][26] Today, these 2D materials are widely utilized by various research groups to design SPR-based biosensors, which are capable of detecting different biomolecules due to the robust interaction of biomolecules present in the analyte. 27,28 The fabrication of such materials is easier because they belong to the category of organic nanomaterials. Generally, the electrospinning fabrication technique is used for the fabrication of organic nanomaterials because it is a safe, swi, smooth, and cost-effective fabrication.…”