Abstract
Photomodification of transparent dielectric materials, induced by tightly focused laser beams, can be utilized for the fabrication of 3 D photonic crystal (PhC) structures. The photomodification occurs in the focal region of the beam due to multiphoton absorption. Nonlinearity of this process allows to reduce the size of the photomodified region even below the diffractive limit of the focusing optics. We utilize two types of photomodification for the PhC fabrication: (i) damage in silica glass that leaves empty voxels, and (ii) polymerization in liquid resins that leaves solid voxels. By damaging/solidifying the initial materials at precisely controlled periodic locations, we have recorded 3 D PhC structures. Using the (i) process we have recorded PhCs in silica with 3 D fcc lattice types, which exhibit clear signatures of photonic bandgaps in the near IR spectral region. With (ii) process we have recorded log-pile PhC structures, which exhibit photonic bandgaps and microcavity effects in the same spectral region.
