Direct Wide-angle Measurement of Photonic Band- structure in a Three-dimensional Photonic Crystal using Infrared Fourier Imaging Spectroscopy

We propose a method to directly visualize the photonic band-structure of micron size photonic crystals using wide angle spectroscopy. By extending Fourier Imaging Spectroscopy sensitivity into the infrared range we have obtained accurate measurements of the band-structures along the high-symmetry directions (X-W-K-L-U) of polymeric three-dimensional rod-connected diamond photonic crystals. Our implementation also allows us to record single-wavelength reflectance far field patterns showing a very good agreement with simulations of the same designs. This technique is suitable for the characterization of photonic structures working in the infrared and in particular, to obtain band-structure information of complete photonic band gap materials.