Silicon Periodic Structures and their Liquid Crystal Composites
This paper summarises results on the design, fabrication and characterisation of one-dimensional (1D) Photonic Crystals (PCs) for silicon micro-photonics. Anisotropic and photo-electrochemical etching were used to obtain silicon wall arrays with a high aspect ratio. The characteristics of these wet etching techniques, including their advantages and disadvantages are considered. Optical reflection and transmission spectra of the photonic structures fabricated were characterised by Fourier Transform Infra-Red (FTIR) micro-spectroscopy over a wide spectral range of =1.5-14.5m. These measurements reveal that side-wall roughness impacts the optical properties of 1D PCs. Problems associated with Photonic Band-Gap (PBG) tuning in periodic structures infiltrated with nematic liquid crystals are discussed. A design of a composite 1D PC on an SOI platform for electro-tuning is proposed. The structure was fabricated and tuning due to an electro-optical effect with E7 liquid crystal filler was demonstrated.
M. Kittler and H. Richter
E. V. Astrova et al., "Silicon Periodic Structures and their Liquid Crystal Composites", Solid State Phenomena, Vols. 156-158, pp. 547-554, 2010