[nano501] Nano 501 Tutorial, Wednesday, Jan. 30, 2:30 pm

[Goodman, Alicia D.]

Three-Demensional Photonic Crystals
Minghao Qi
Wednesday, January 30, 2008, 2:30 pm, EE 317

A photonic crystal (PhCs) is typically a composite of a 
high-dielectric-constant material (e.g. Si) and a low-constant one (e.g. 
SiO2 or air), arranged periodically in space. Two dimensional examples 
include a hexagonal lattice of air holes drilled in a Si slab, or a set 
of Si rods at square lattice points. In some 3D configurations, photonic 
band gaps (PBGs) are formed such that photons over a certain frequency 
band cannot propagate in any directions.

When the perfect periodicity is broken, e.g. a single hole filled or a 
single rod removed, point defects (or microcavities) are formed. 
Compared to cavities in 2D PhCs, the quality factors (Qs) currently 
achieved are lower. However, the Qs can be improved exponentially with 
increasing number of layers surrounding the cavities. The ultimate Q 
achievable is limited only by intrinsic material absorption. 3D PhCs 
also have the unique advantage that light can be confined in hollow 
microcavities. Another distinctive feature for a cavity in 3D PhCs is 
that the Q will not degrade with the presence of structural distortions. 
This makes it much more feasible to realize such cavities with 
nanofabrication. Finally, increasing the cavity Q in a 3D PhC does not 
require delocalization, or increase of mode-volume.

Microcavities in 3D PhCs can be applied to explore a variety of 
fundamentally important physical phenomena. For example, high Q cavities 
with mode volumes approaching (1/2 λ/n)3 are ideal for studying cavity 
quantum electrodynamics (CQED). We show that with dynamic tuning of 
high-Q cavities, a scheme for on-demand single-photon emission could be 
realized in 3D PhCs.

-- 

Alicia Goodman
Administrative Assistant
Network for Computational Nanotechnology
Purdue University
Birck Nanotechnology Center
1205 West State Street
West Lafayette, IN  47907
Phone:  765-494-7715
Fax:  765-494-0811
email:  goodman at purdue.edu
website:  www.nanoHUB.org

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