Photonic crystal composites-based wide-band optical collimator

Abstract

Photonic crystal ͑PC͒ composites are sequenced series of PCs that feature the same periods but different filling fractions. By properly tuning the filling fractions of the individual PCs and merging the working band of each PC into a continuous frequency range, wide-band self-collimation of optical signals can be realized. The band diagrams and the equal-frequency contours of the PC structures were calculated through the plane wave expansion method and the finite-difference time-domain method was employed to simulate the propagation of electromagnetic waves through the PC structures. Our results show that while a single PC can only collimate optical waves over a narrow frequency range, a PC composite exhibits a much wider collimation band. Such a wide-band optical collimation lens can be useful in applications that demand directional optical energy flow over a long distance, such as optical imaging and biosensing.

Extraordinary refractive properties of photonic crystals of metallic nanorods

“…This implies that, in this case, at any angle of incidence, the group velocity and thus the energy flow of the transmitted wave will be directed along the same direction, namely the z direction. This phenomenon, so called self-collimation [57], has already been reported for 2D and 3D dielectric photonic crystals [58][59][60], and can be useful in the design of integrated optics circuits and other applications [61].…”

Phase-controlling phononic crystal

“…16-28 These properties parallel many of those found in photonic crystals. 29,30 The -space and k-space properties are directly related to the size, geometry, scale, and composition of the constitutive materials of the PC.In the present letter, we demonstrate that the band structure of a two-dimensional PC constituted of a square array of cylindrical polyvinylchloride ͑PVC͒ inclusions in an air matrix can be used to control the relative phase of elastic waves. Phase control is due to the propagation of elastic waves in the PC with wave vectors that are not collinear with their group velocity vectors.…”

“…[16][17][18][19][20][21][22][23][24][25][26][27][28] These properties parallel many of those found in photonic crystals. 29,30 The -space and k-space properties are directly related to the size, geometry, scale, and composition of the constitutive materials of the PC.…”

Island photonic structures: Properties and application in sensing and metrology

“…If the filling factor of a 2D photonic crystal is properly tuned over the structure, a wide-band selfcollimation effect can arise for optical signals [16]. The results obtained using the finite-difference time-domain simulation of the electromagnetic wave propagation through the structure has shown distinctive wide-band self-collimation of optical rays and other flat lens properties.…”