Optical characterisation of 2D macroporous silicon photonic crystals with bandgaps around 3.5 and 1.3 μm

Transmission measurements were performed on thin 2D silicon photonic crystals (PCs) with 1-4 crystal rows in order to investigate the effect of a finite structure and to obtain an estimate of the crystal thickness necessary to minimize crosstalk between adjacent waveguides, For wavelengths deep within the H-bandgap a strong exponential decay revealing an attenuation constant of 10 dB per crystal row was measured. For opto-electronic applications, the lattice constant of macroporous Si was successfully downscaled from a pitch of 1.5 to 0.5 mum. Reflection measurements performed at these structures show good agreement with corresponding bandstructure calculations exhibiting a complete bandgap around lambda = 1.3 mum. (C) 2001 Elsevier Science B.V. All rights reserved.