Unusual refractions in photonic crystals based on polymer-dispersed liquid crystal films

摘要

This work describes unusual refractive phenomena from a hexagonally close-packed (hcp) photonic crystal (PC) based on a holographic polymer dispersed liquid crystal film. The refracted collimated beams comprise positive and negative refractions and can be switched to exhibit the negative refraction part only by changing the incident angle or the wavelength of the incident beam. The equal frequency surfaces are adopted to analyze the refractions of light both inside and outside the hcp PC.