  We present the simulation, fabrication, and optical characterization of
low-index polymeric rod-connected diamond (RCD) structures. Such complex
three-dimensional photonic crystal structures are created via direct laser
writing by two-photon polymerization. To our knowledge, this is the first
measurement at near-infrared wavelengths, showing partial photonic bandgaps for
this structure. We characterize structures in transmission and reflection using
angular resolved Fourier image spectroscopy to visualize the band structure.
Comparison of the numerical simulations of such structures with the
experimentally measured data show good agreement for both P- and
S-polarizations.
