Superprism phenomena in 3D photonic crystals fabricated by two-photon polymerisation

Abstract

Since the publications of E. Yablonovitch and S. John on the optical properties of periodic, dielectric structures in the year 1987 there have been intensive research efforts related to the design and new methods for the fabrication of functional photonic crystal devices. Many of these investigations addressed the realization of high refractive index structures possessing a complete photonic band gap (PBG). Due to their low refractive indices of approximately 1.5 to 1.6, polymer photonic crystals cannot have a complete PBG and were therefore mainly considered as templates for their replication using high index materials. Here we present theoretical as well as experimental evidence for wavelength dependent super-refraction phenomena in superprisms based on polymer woodpile structures. The results show the great potential of these low refractive index three-dimensional crystals, fabricated in a very fast and single-step process, to serve directly as functional micro-optical devices in the near infrared wavelength regime.Since the publications of E. Yablonovitch and S. John on the optical properties of periodic, dielectric structures in the year 1987 there have been intensive research efforts related to the design and new methods for the fabrication of functional photonic crystal devices. Many of these investigations addressed the realization of high refractive index structures possessing a complete photonic band gap (PBG). Due to their low refractive indices of approximately 1.5 to 1.6, polymer photonic crystals cannot have a complete PBG and were therefore mainly considered as templates for their replication using high index materials. Here we present theoretical as well as experimental evidence for wavelength dependent super-refraction phenomena in superprisms based on polymer woodpile structures. The results show the great potential of these low refractive index three-dimensional crystals, fabricated in a very fast and single-step process, to serve directly as functional micro-optical devices in the near infrared wave...