title: Negative refraction angular characterization in one-dimensional photonic crystals.
abstract: BACKGROUND
  Photonic crystals are artificial structures that have periodic dielectric components with different refractive indices. Under certain conditions, they abnormally refract the light, a phenomenon called negative refraction. Here we experimentally characterize negative refraction in a one dimensional photonic crystal structure; near the low frequency edge of the fourth photonic bandgap. We compare the experimental results with current theory and a theory based on the group velocity developed here. We also analytically derived the negative refraction correctness condition that gives the angular region where negative refraction occurs.
  
  
  RESULTS
  By using standard photonic techniques we experimentally determined the relationship between incidence and negative refraction angles and found the negative refraction range by applying the correctness condition. In order to compare both theories with experimental results an output refraction correction was utilized. The correction uses Snell's law and an effective refractive index based on two effective dielectric constants. We found good agreement between experiment and both theories in the negative refraction zone.
  
  
  CONCLUSIONS
  Since both theories and the experimental observations agreed well in the negative refraction region, we can use both negative refraction theories plus the output correction to predict negative refraction angles. This can be very useful from a practical point of view for space filtering applications such as a photonic demultiplexer or for sensing applications.
authors.affiliation: Visual Psychophysics and Perception Laboratory, School of Optometry, University of Montreal, Montreal, Quebec, Canada. je.lugo.arce@umontreal.ca
authors.forename: Jesus Eduardo
authors.initials: JE
authors.lastname: Lugo
authors.forename: Rafael
authors.initials: R
authors.lastname: Doti
authors.forename: Jocelyn
authors.initials: J
authors.lastname: Faubert
mesh_terms: D003460:Crystallization; D017785:Photons; D012031:Refractometry