In this paper, we present both numerical and experimental results for the waveguiding of light using a low-index-contrast
(LIC) self-collimating photonic crystal (SCPhC) in the RF frequency regime. This waveguiding structure
utilizes the unique interactions of light with the periodic structure of the photonic crystal (PhC) to propagate a beam
of light without divergence. This design also employs materials with a low index contrast (LIC), which reduces the
electromagnetic signature of the PhC. This SCPhC was designed by extracting its dispersion contours and
numerically simulating it using HFSS, a commercial 3-D, full-wave FEM software.
In particular, we addressed the issue of coupling the PhC to a coaxial medium by designing an input/output (I/O)
coupler consisting of a coaxial-to-waveguide transition, a rectangular waveguide and a tapered dielectric transition.
We fabricated the SCPhC with a rigid polyurethane foam slab and Rexolite polystyrene rods using an automated
CNC router to drill the periodic lattice in the slab. We also fabricated the dielectric segments of the I/O couplers
with Rexolite slabs using an automated milling machine. Using these I/O couplers and SCPhC slab, we simulated
and subsequently measured experimentally an insertion loss, for the entire system, of -3.3 dB through a 24" PhC
slab, and a coupling loss of -0.95 dB at each coupler-PhC interface.