From the cover story

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Photonic Crystal
From the cover story of October 2006 Physics
Today
Ming Li PhD Candidate Department of Physics and
Astronomy Iowa State University http//www.public.
iastate.edu/mli/
November 3rd, 2006
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Cover story Structure Color VS. Pigment color
Opal
Sea mouse
Periodic structure offers the ability to control
light propagation. Reflection from those
structures are strongly wavelength
sensitive which makes the iridescence color.
Peacock feather
OPN, Feb, 2003
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Outlines

• Part I
• History of photonic crystal
• Comparison between photon and electron
• Introduce defects into photonic crystal
• Part II
• Sound wave, water wave etc
• Part III
• Recent progress in my group

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• Part I
• History of photonic crystal
• Comparison between photon and electron
• Introduce defects into photonic crystal

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Long history about material
What else?
Pictures from Google search
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History of photonic crystal
More fun to play Defects etc
http//ab-initio.mit.edu/photons/
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Crystal VS. Photonic Crystal
Major differences (1) dimension and lattice
constant crystal at order of Å (2) Scale
properties (length scale) Maxwell equation does
not have length scale. (3) There are interaction
between electrons, but no interaction between
photons (4) Crystal has been studied for a long
time and various applications have been
proposed. Photonic crystal is only at the
starting stage.
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EM Spectrum
At Microwave region, there are some device
already used to control propagation of EM
metallic waveguide and metallic cavity.
EM Spectrum
Iowa State University
Hebei Normal University
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Introduce defects into Photonic Crystal
Point Defect (Cavity)
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Introduce defects into Photonic Crystal
Line defect (waveguide)
Line point defect (Channel drop filter)
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Future applications from photonic crystal

• High Q value resonant cavity for laser
• small in size while high in power and
  efficiency.
• Lossless waveguide for optical integrated
  circuit
• acting like wire at IC.
• Basic devices for optical integrated circuit
• acting like transistor or gate at IC.
• Design for medical instrument or defense system.
• Improve solid state lighting to save energy.

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Part II Sound wave, water wave etc
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Sonic (phononic, or acoustic) crystal
Phononic band gap
Trapping sound in defect
Applications (1) Novel sound manipulation
devices, such as sound mirror (2) Improve light
emission at indirect semi-conductor by
controlling photons (3) Control thermal energy
(by phonons) (4) Phonon Laser intense sources
of coherent monochromatic phonons
Physicsweb Dec. 2005
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One page Nature article of Phononic crystal.
Art part Sculpture has a periodic square array
of hollow steel cylinders by Eusebio Sempere.
Science part There is a sonic band gap.
The sound attenuation peak is at 1670 Hz (the
first band gap). Measured by Francisco Meseguer.
This happened at 1995.
ISU is one of the first groups to get start on
phononic crystal study from 1992.
From Art to Science
Nature 378 241
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Water wave crystal
Focus sea wave that could provide useful for
water-energy applications by putting array of
cylinders fixed to the sea bed.
normal refraction
negative refraction
negative refraction
copper cylinders in a square 10  10 mm lattice
Zi Jian _at_ Fudan Univ. Hu Xinhua _at_ ISU
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Time for wave engineering!!

• Electron wave in crystal
• Electromagnetic wave in photonic crystal
• Sound wave in phonotic crystal
• Heat transportation (by phonons) in phonontic
  crystal
• Water wave in ??? crystal
• All other mechanical waves in periodic structures

All lead to a new concept of wave engineering,
but at the same time has already been studied
for a long time
Control the dispersion relation for various
applications
Physicsweb Dec. 2005
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• Part III
• Recent progress in my group

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What do we do in our group? (a) Microwave
experiment
Curves TMM calculation results symbols
microwave experimental
Ming Li _at_ ISU
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What do we do in our group? (b) TMM (calculation
method)
(1) The planewave basis makes Maxwell Equations
a linear algebra problem. (2) Transfer
matrix method make 3D problem into 2D
slices to save memory usage and fast
calcualtion. (3) It is a frequency domain method
and calculation results are all for steady
state and very accurate which makes
interpolation only a few frequency points
possible
Incident Wave (Frequency etc)
Spectrum
Transfer Matrix Method
Real Space Lattice Configuration
Mode shape
Plan Wave Setup
Band diagram
Ming Li _at_ ISU
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What do we do in our group? (c) IR and optical
wave length fabrication.
Now lets go back to the cover of Physics today.
We are trying to fabricate structures close to
the optical frequency range which adds another
option for generating color the structure color.
JH Lee _at_ ISU
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Thank you Have a nice weekend!
http//www.public.iastate.edu/mli