Transmission of a microcavity structure in a two-dimensional photonic crystal based on macroporous silicon

Photonic crystals consist of regularly arranged dielectric scatterers of di mensions on a wavelength scale, exhibiting band gaps for photons, analogous to the case of electrons in semiconductors. Using electrochemical pore for mation in n-type silicon, we fabricated photonic crystals consisting of air cylinders in silicon. The starting positions of the pores were photolithog raphically pre-defined to form a hexagonal lattice of a = 1.58 mum. The pho tonic crystal was microstructured to make the photonic lattice accessible f or optical characterization. Samples with different filling factors were fa bricated to verify the gap map of electric and magnetic modes using Fourier -transform infrared (IR) spectroscopy. The complete band gap could be tuned from 3.3 to 4.3 mum wavelength. We were able to embed defects such as wave guide structures or microcavities by omitting certain pores. We carried out transmission measurements using a tunable mid-IR optical parametric oscill ator. The resonance is compared with theoretical expectations. (C) 2001 Els evier Science Ltd. All rights reserved.