Direct laser writing of optical field concentrators based on chirped three-dimensional photonic crystals

We describe fabrication and properties of 3D photonic crystals with chirped lattice period using Direct Laser Write lithography technique in photoresists, and report on the optical properties of the fabricated structures. Experimental demonstration that the fabricated structures can be used as concentrators of electromagnetic radiation along the direction of propagation at optical frequencies is reported. Potential applications of chirped photonic crystal in improved optical detectors are discussed.