Anisotropic photonic properties of stretched polymer inverse opal

Abstract

In recent years, there has been vast interest in the study of photonic crystal which has unique ability to control the propagation of light. The propagation of electromagnetic waves within a certain frequency region are forbidden, is known as photonic band gap (PBG). As a kind of advanced optical material, photonic crystals have exhibited extensive applications to optical field such as laser, optical fiber, and quantum optical devices. Compared with traditional photonic crystal with isotropic PBG, anisotropic photonic crystal attracts researcherspsila more interest for its peculiar properties. Recently, we constructed a kind of anisotropic photonic crystal by stretching polymer inverse opal. By uniaxial stretching process, the refractive index of some polymer became anisotropic, which could cause the anisotropy of PBG. The original air spheres in inverse opal became elliptic with the major axis parallels to the stretching direction but without destroying the structural ordering. As result, the PBG is anisotropic and dependent on the direction of linearly polarized light. Showing in reflection spectrum, the position reflection peak shifted when the polarizing direction of linearly polarized light change from the direction parallel to the drawing axis to perpendicular direction. Such unique optical properties of the anisotropic photonic crystal provided a new approach for the separate design of the stopband at different polarization. Applications in polarizing display, polarizing beamsplitter, polarization-holding optical waveguide, and so on are anticipated.