Photonic Band Gap Materials
The
Race for the Photonic Chip:Opal-Patterned Chip, Colloidal Crystal Assembly
in Silicon Wafers
By Geoffrey A. Ozin and San Ming Yang
This paper briefly surveys recent developments in engineering physics
approaches and self-assembly chemistry methodologies
for creating 3-D photonic crystals and how this has led to in-wafer patterned
colloidal crystals. These materials are comprised of single crystal micrometer
scale features of silica colloidal crystals that have controlled thickness,
area and orientation and are embedded within a single crystal silicon wafer.
Two processes for growing opal-patterned chips are described. One is based
upon microfluidic and the other spin coating driven self-assembly of colloidal
dimension silica micro-spheres within a lithographic patterned silicon wafer.
These are both straightforward, rapid, and reproducible chemical procedures that may possibly
be integrated into existing chip fabrication processes and could be amenable
to mass production. Opal-patterned chips may provide an enabling technology
for engineering photonic crystal lattices, photonic band structures and defects
in 3-D photonic crystals that have stop bands or complete photonic band gaps
operating at visible or near infrared wavelengths. These advances in 3-D photonic
crystals if reduced to practice could pave the way to an amalgamation of photonic
crystal devices with optical fibers on chips for future photonic integrated
circuits, computer and telecommunication systems.
Flash Presentation: Opal on a
Chip
Desktop background:
Opal on a chip background
Published
Articles:
Chem.
Commun., 2000, 2507–2508
Adv.
Funct. Mater. 2001, 11, No. 2, April
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Inverted Silicon Opal:
The race is on
We have recently succeeded in making
a 3D Silicon Photonic Crystal with a complete bandgap at 1.5 µm. These
results are reported in Nature,
published in the May 25th, 2000 issue, along with a short piece in the
News & Views
section.
The Canadian Institute for Advanced
Research has issued a press release about the discovery, and many journalists have
covered the story. Our recent paper in Advanced
Materials summarizes our research in shaping silicon over all
length scales.
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You will need MPEG software such as
Windows Media Player
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News articles about our silicon PBG materials:
(if you know of any
others, please let Emmanuel
know)
Properties of Photonic Band Gap Materials
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“This is the next trilliondollar industry.”
--
Gerard Lynch, President & CEO, Photonics Research Ontario
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Since the invention of the laser, the field
of photonics has progressed through the development of engineered materials
which mold the flow of light. Photonic band gap (PBG) materials are a new
class of dielectrics which are the photonic analogues of semiconductors. The
photonic band gap is a frequency interval over which the linear electromagnetic
propagation effects have been turned off.
Unlike semiconductors, which facilitate the
coherent propagation of electrons, PBG materials facilitate the coherent localization
of photons. Applications include zero-threshold micro-lasers with high modulation
speed and low threshold optical switches and all-optical transistors for optical
telecommunications and high speed optical computers.
In a PBG, lasing can occur with zero pumping
threshold. Lasing can also occur without mirrors and without a cavity mode
since each atom creates its own localized photon mode. This suggests that
large arrays of nearly lossless microlasers for all-optical circuits can be
fabricated with PBG materials.
Near a photonic band edge, the photon density
of states exhibits singularities which cause collective light emission to
take place at a much faster rate than in ordinary vacuum. Microlasers operating
near a photonic band edge will exhibit ultrafast modulation and switching
speeds for application in high speed data transfer and computing.
Applications such as telecommunications,
data transfer, and computing will be greatly enhanced through all-optical
processing in which bits of information, encoded in the form of a photon number
distribution, can be transmitted and processed without conversion to and from
electrical signals.
The PBG material provides dopant atoms with
a high degree of protection from damping effects of spontaneous emission and
dipole dephasing. In this case the two-level atom may act as a two-level quantum
mechanical register or single photon logic gate for all optical quantum computing.
For more information please contact
Nicolas Tetreaulti: ntetreau@chem.utoronto.ca/
