Transcript Silicon-on-Insulator (SOI) - Centre for Research in Photonics

Silicon-on-Insulator (SOI) based
Nanophotonics devices and their
Applications
Sawsan Abdul-Majid
Center for Research in Photonics( CRPuO)
University of Ottawa
23. Feb.2012
University of Ottawa / CRPuO
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The oldest and largest officially bilingual university in North America
Close proximity to Federal Government Research Laboratories CRC &
NRC IMS/CPFC
• Prof. Trevor Hall, established CRPuO in 2002
• PTLab (Photonics Technology Laboratory)
Canada Research Chairs
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CRC-I in Fibre Optics and Photonics (X. Bao)
CRC-I in Ultra-fast Photonics (T. Brabec)
CRC-II in Ultrafast Laser-Matter Interactions (R. Bharwaj-Vedula)
CRC-I in Attosceond Science (P. Corkum)
CRC-I in Photonic Network Technology (T. Hall)
CRC-II in Photonic Nanostructures & Device Integration (K. Hinzer)
CRC-II in Computational Nanophotonics (L. Ramunno)
CRC-I in Applied Photochemistry (J. C. Scaiano)
CERC in Quantum Nonlinear Optics (Robert Boyd)
Outline:
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Digital Radio-over-fiber (RoF) technology
Coherently detected RoF systems
Phase relationships
Silicon photonics projects at CRPuO
Small size MMI, 90 degree optical hybrid in a
digital coherent receiver.
• Recent work, nanophotonics devices, OpSiS IME process, with the support of CMC
• Conclusion
• Acknowledgment
Hamim Nasoha 1 and Sevia M. Idrus2,Modeling and Performance Analysis of
WCDMA Radio over Fiber System. 1,Photonics Technology Center,
2,Faculty of Electrical Engineering, University Technology of Malaysia , APAC2007
Radio-over-Fiber (RoF) technology entails the use of optical fiber links to
distribute RF signals from a central location to simplified Remote Antenna
Units (RAUs)
 Ubiquitous connectivity: increase both transmission capacity and
coverage.
 Lower energy consumption
Radio-over-fiber (ROF)
technology
 Radio frequency (RF) wireless provides the end user with the
convenience of an untethered connection whilst the optical
network provides a high capacity, low attenuation, interferencefree medium to transport RF signals to distributed antenna units.
 Large-scale deployment warrants device integration to access the
economics of volume manufacture
 Access network technology is advancing rapidly to provide greater
reach, to serve increasing numbers of users, and to accommodate
increasing demand for bandwidth. The convenience of ‘untethered’
operation is driving the convergence of wireless and fibre access
networks.
Digitised Vs. Analogue Radio-over-Fibre
Ampalavanapillai Nirmalathas, Prasanna A. Gamage, Christina Lim, Dalma Novak, Rod Waterhouse, Yizhuo Yang,
‘Digitized RF transmission over fiber’, IEEE Microwave Magazine, June 2009, pp. 75-81.
a) Analogue RF synthesised in the
digital domain and transported over
analogue optical link.
b) Digitised RF transported over digital
optical link.
Lower energy consumption is
claimed.
RF synthesised as baseband digital I &
Q channels. Scheme suggests digital
synthesis of real IF channel from digital
I &Q channels with up conversion
relying on replication of spectrum due
to sampling.
Transport of digital baseband I &Q
data with up conversion by traditional
means at the remote antenna unit likely
necessary in practice?
DROF/ Lower Energy consumption
Yizhuo Yang , Christina Lim, and Ampalavanapillai Nirmalathas, Comparison of Energy
Consumption of Integrated Optical Wireless Access Network, OSA/OFC,NFOEC 2011.
Silicon Photonics projects at CRPuO
 Our proposal is to dispense with the DACADC block and use a digital coherent optical
link with a modern digital receiver at the
other end.
 Coherently detected RoF systems would
enable the information to be carried in both
the amplitude and phase or in different
states of the polarization of the optical Field.
 Additionally, the selectivity of coherent
receiver is very well suited for access
networks
CRPUO project :900 Optical Hybrid
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Compact 90º optical hybrid, built on small size SOI waveguide
technology (1.5 μm SOI -based rib waveguide, with 0.8μm rib height)
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Critical component of a potentially low-cost coherent optical receiver
design developed within the frame of our Optical Coherent
Transmission for Access Network Extensions (OCTANE) project
Silicon on Insulator( SOI)
waveguides
Wa
width
H-h, rib height
Si top layer
SiO2 layer
Si substrate
A-SOI wafer before fabrication
B-Waveguide cross-sectional view (After
fabrication)
Small size SOI Multimode Interference
Couplers
 In recent years, there has been a growing
interest in the application of multimode
interference (MMI) effects in integrated optics.
 Optical devices based on MMI effects, have
excellent properties and ease of fabrication.
 They have been rapidly incorporated in more
complex Photonics integrated circuits (PICs)
such as phase diversity networks, MachZehnder switches and modulators, balanced
coherent receivers, and phase array switches.
Multimode Interference Couplers
The central structure of an MMI device is a waveguide designed to support a
large number of modes (typically > 3). In order to launch light into and
recover light from that multimode waveguide, a number of access (usually
singlemoded) waveguides are placed at its beginning and at its end. Such
devices are generally referred to as N x M MMI couplers, where N and M are
the number of input and output
The figure below shows 2x2 MMI coupler
Designed Polarization independent 2x2
MMI, based on small size SOI
• Excess insertion loss was found to improve with wider input mode sizes
which required access waveguides wider than the single-mode limit.
To excite only the fundamental mode an adiabatic taper of length 100 um is
added.
A ( TE)
48.5% transmission in the top
branch (straight through case)
and 48.8% in the bottom branch
(cross-over case
B (TM)
48.8%Transmission in the top branch,
straight through case) ,and 48.8%
Transmission in the bottom branch
(crossover case)
900 Optical Hybrid, based on
self imaging principle
 The outputs of the optical hybrid is a liner combination of two
input fields.
 optical fields at the four output ports are proportional to
 E1+j E3, E1-E3,E1+E3,E1-jE3, where E1 and E3 are the optical
fields at ports 1 and 3. The relative phase shift, at the output
ports is π/2, and 3π/2.
4x4 MMI simulation
Total length
=3712.5μm
Exciting port 1
Exciting port 3
Sawsan M.& Imad H./
CRP at the university of
Ottawa
Simulation results of the 4x4 MMI
using FIIMPROB
Fabricated small size SOI MMI
Experimental results for 2x2 and 4x4
MMI
Simulated spectral interferograms at the four output ports over the
wavelength range (1552-1558) nm for a path length difference of
1.5mm Inserted between the two input ports of the 90º hybrid
Results of simulating output power and
phases for TE excitation to port 3
Our experimental results
PMF
Measured transmission spectra for
TE at 4 output ports at MMI
Experimental results
(a) Extracted phases at the four output ports, (b) relative phases at the
output ports with respect to port #1, (c) phase difference between output #2
and #3, (d) phase difference between output port #1 and #4.
phase relationship among different output ports remains stable across the 20nm spectral bandwidth
CRPUO project: Nano wire SOI
Fully passive Si-photonic 90° hybrid for coherent receiver, ECOC Technical Digest © 2011 OSA
applications
K. Voigt (1), L. Zimmermann (1,2), G. Winzer (1), H. Tian (2), B. Tillack (1,2), K. Petermann (1)
(1) TU-Berlin, Joint Lab Silicon Photonics, Einsteinufer25, 10587 Berlin, Germany
(2) IHP Microelectronics GmbH, Im Technologiepark, 15236 Frankfurt (Oder), Germany
[email protected]
For fabrication of 90° hybrids they used ((200 mm SOI wafers)) with silicon
thickness of 0.22 μm and a 2 μm buried oxide layer
The single MMI device requires a footprint of about 10μm × 200μm.
CRPUO project 2: SOI Nano wire
A: Passive 4x4 MMI
• L= 131.25micron
• Width= 8.5 Micron
• Phase difference
between portt1
and 4 is Zero,
• Port 2, and 3 is
0.48
Our fabrication design for Opsis
fabrication run#1
 2x2 MMI, 4x4 MMI, S bends , straight
Passive
 waveguides( test structures)
 Phase array switches
 E/O, and Thermal switches.
 PIN photo diodes
 Complete system passive + active
Active
Recent nano wire Design
Phase shifters switch
Edge
couplers
E/O Modulator
4x4 MMI
2x2 MMI
Phase Shifters / Thermal
4x4 MMI
4x4 MMI
4 Thermal
Modulators
Ge detectors
Conclusion
• Small size polarization independent SOI 90 Coherent detector
based on self imaging principle was designed, fabricated and
tested at our facilities at Ptlab.
• Nano scale 2x2 MMI and 4x4 MMI were designed, simulated
and included in the recent fabrication run at Opsis (supported
by CMC)
• Phase array switch using E/O, and Thermal modulators were
designed and included in the same wafer .
• After fabrication the chips will be tested here at CRPuO.
Acknowledgment
 This first project was supported by the Natural
Sciences and Engineering Research Council of
Canada (NSERC) under the framework of the Optical
Coherent Transmission for Access Network
Extensions (OCTANE) project.
 We are grateful to CMC Microsystems for their
support of fabrication at CPFC, and for supporting us
with the IME-Opsis first fabrication run (second
project).
 Grateful for assistance provided by Enablence Inc ,
Photon Design, and Prof. Winnie Ye (Carlton
University).
 Special thanks to the team (Dr. Imad Hassan, Qi
Zhang and Prof. Trevor Hall)