Three-dimensional metallic photonic crystals fabricated by soft lithography for midinfrared applications

We present an efficient method of fabricating freestanding three-dimensional metallic photonic crystals using soft lithography. Low cost and ease of fabrication are achieved through gold sputter deposition on a freestanding woodpile polymer template. We compare experimental results to theoretical calculations for tetragonal and face-centered-tetragonal structures as a function of the number of layers. The photonic crystals behave like full metallic structures with a photonic band edge at a wavelength of $3.5μm$⁠. The rejection rates of the structures are about $10dB$/layer.