第八章光子晶体.ppt

第七章 光子晶体 photonic crystal Layer-by-Layer Lithography A Layered StructureWe’ve Seen Already Making Rods Holes Simultaneously Making Rods Holes Simultaneously Making Rods Holes Simultaneously Making Rods Holes Simultaneously Making Rods Holes Simultaneously Making Rods Holes Simultaneously Making Rods Holes Simultaneously Making Rods Holes Simultaneously Making Rods Holes Simultaneously A More Realistic Schematic e-beam Fabrication: Top View e-beam Fabrication: Side Views(cleaving worst sample) X-ray Interference Lithography From Rectangular to Hexagonal enough layer-by-layer already! Mass-production II: Colloids Mass-production II: Colloids Inverse Opals Inverse-Opal Photonic Crystal “It’s only wafer-thin.” [ S. Noda et al., Science 289, 604 (2000) ] [ M. Python ] Woodpile Gap from 1.3–1.55μm [ S. Noda et al., Science 289, 604 (2000) ] Yes, it works: Gap at ~4μm [ K. Aoki et al., Nature Materials 2 (2), 117 (2003) ] 1μm 50nm accuracy: (gap effects are limited by finite lateral size) 20 layers A Metal Photonic Crystal [ J. G. Fleming et al., Nature 417, 52 (2002) ] Start with Si woodpile in SiO2… dissolve Si with KOH… fill with Tungsten via chemical vapor deposition (CVD) (on thin TiN layer) dissolve SiO2 with HF… A Two-Photon Woodpile Crystal [ B. H. Cumpston et al., Nature 398, 51 (1999) ] (much work on materials with lower power 2-photon process) Difficult topologies ? Arbitrary lattice ? No “mask” ? Fast/cheap prototyping [ fig. courtesy J. W. Perry, U. Arizona ] One-PhotonHolographic Lithography [ D. N. Sharp et al., Opt. Quant. Elec. 34, 3 (2002) ] absorptive material Four beams make 3d-periodic interference pattern (1.4μm) k-vector differences give reciprocal lattice vectors (i.e. periodicity) beam polarizations + amplitudes (8 parameters) give unit cell One-PhotonHolographic Lithography [ D. N. Sharp et al., Opt. Quant. Elec. 34, 3 (2002) ] huge volumes, long-range periodic, fcc lattice…backfill for high contrast 10μm One-PhotonHolographic Litho