Thermal tunable one-dimensional photonic crystals containing phase change material*

Abstract

To obtain the adjustable photonic crystals (PCs), we numerically investigate one-dimensional (1D) PCs with alternating VO2 and SiO2 layers through transfer matrix method. The dispersion relation agrees well with the transmittance obtained by the finite element calculation. Tunable band gaps are achieved with the thermal stimuli of VO2, which has two crystal structures. The monoclinic crystal structure VO2 (R) at low temperature exhibits insulating property, and the high temperature square rutile structure VO2 (M) presents metal state. Concretely, the bandwidth is getting narrower and red shift occurs with the higher temperature in VO2 (R)/SiO2 PCs structure. Based on the phase change characteristics of VO2, we can flexibly adjust the original structure as VO2 (R)/VO2 (M)/SiO2. By increasing the phase ratio of VO2 (R) to VO2 (M), the band gap width gradually becomes wider and blue shift occurs. The discrete layers of gradient composites on the dispersion of 1D PCs are also investigated, which enhances the feasibility in practical operation. Thus, our proposed thermal modulation PCs structure paves a new way to realize thermal tunable optical filters and sensors.

Photonic bandgap engineering in (VO2) n /(WSe2) n photonic superlattice for versatile near- and mid-infrared phase transition applications

“…Generally, there is a shift in the transmission curves to lower wavelengths under the H VO 2 condition. Similar results were conducted on VO 2 (R)/VO 2 (M)/SiO 2 with a wider bandgap resulting in a blue shift [70]. By increasing the thickness of the VO 2 layer, the PhB starts to appear in the more extended wavelength parts.…”

Dual-Polarization Topological Interface States in Ridge Photonic Crystals

“…40 Interestingly, these interface states carry transverse spin, which enable unidirectional excitation of interface states (see more details in Figure S5). Interface states of ridge photonic crystals can be modulated by using phase change materials 41 or soft materials. 42 Topologically protected interface states can survive even when the refractive indices of the materials deviate in a wide range, until the original DNR with finite radius shrinks to a point (see more details in Figure S4).…”

A simple and comprehensive electromagnetic theory uncovering complete picture of light transport in birefringent crystals

“…Our theory not only reproduce some basic phenomena such as birefringence production, the refraction angle, the refractive index, and index ellipse, but also predict many other relevant physical and optical quantities. This method can also be utilized to study the light transport behaviors in various anisotropic situations, such as photonic crystals, [14] gyromagnetic material systems, [15] and metamaterial structures. [16]…”