Integrated High Order Filters in AlGaAs Waveguides with up to Eight SideCoupled Racetrack Microreson

1
Integrated High Order Filters in AlGaAs
Waveguides with up to Eight Side-Coupled
Racetrack Microresonators

• Rajiv Iyer, Francesca Pozzi, Marc Sorel,
• Zhenshan Yang, Philip Chak, John Sipe, Stewart
  Aitchison
• Department of Electrical and Computer
  Engineering,
• Department of Physics, University of Toronto,
  Toronto, Canada
• Department of Electronics Electrical
  Engineering,
• University of Glasgow, Glasgow, UK

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Overview

• Microrings and SCISSORs
• SCISSOR modeling
• Design and Fabrication of 8 ring AlGaAs SCISSOR
• Experimental Results
• Summary

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Microresonators as Filters
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SCISSOR Structures

• Side-Coupled-Integrated-Spaced-Sequence-Of-Resonat
  ors
• Have been proposed for high-order filtering,
  optical logic, and slow light

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Racetrack SCISSOR
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SCISSOR Modeling
Dz
r
k
s
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Waveguide Design
Spatial modal profiles computed using
Full-vectorial finite-difference analysis neff _at_
1550 nm 2.975
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Experimental Setup
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Results for 8 ring SCISSOR

• 8 ring SCISSOR
• 20.7 micron ring-to-ring separation
• 165 nm coupling gap
• Loss parameter 3.8 cm-1
• k2 0.15 ? 0.13
• neff 2.975 ? 2.967
• TM0 performed significantly better than TE0
• Simulation time
• 2 seconds

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Summary

• Our Hamiltonian formulation of coupled mode
  equations is a fast and useful design tool to
  model high-index contrast structures
• We fabricated an 8-ring SCISSOR structure in
  AlGaAs
• Next steps
• Decrease losses in the device
• Demonstrate
• slow light behavior and nonlinear effects
• THANK YOU

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Integrated High Order Filters in AlGaAs
Waveguides with up to Eight Side-Coupled
Racetrack Microresonators

• Rajiv Iyer, Francesca Pozzi, Marc Sorel, Zhenshan
  Yang, Philip Chak, John Sipe, Stewart Aitchison
• rajiv.iyer_at_utoronto.ca

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References

• 1 V. Van, et. al, Optical signal processing
  using nonlinear semiconductor microring
  resonators, IEEE Journal of Selected Topics in
  Quantum Electronics, Vol. 8, No. 3, 705-713,
  (2002).
• 2 Hryniewicz, et. al, Higher Order Filter
  Response in Coupled Microring Resonators, Phot.
  Tech. Lett., Vol. 12, No. 3, (2000).
• 3 S. Pereira, P. Chak and J. E. Sipe,
  All-optical AND gate by use of a Kerr nonlinear
  microresonator structure, Opt. Lett., Vol. 28,
  No. 6, 444-446 (2003).
• 4 J. E. Heebner, R. W. Boyd, Q-Han Park,
  SCISSOR Solitons and other novel propagation
  effects in microresonator-modified waveguides,
  JOSA B, Vol. 19, No. 4, 722-731 (2002).
• 5 R. Grover, V. Van, T.A. Ibrahim, P.P. Absil,
  L.C. Calhoun, F.G. Johnson, J.V. Hryniewicz,
  P.-T. Ho, Parallel-Cascaded Semiconductor
  Microring Resonators for High-Order and Wide-FSR
  Filters, Jour. Light. Tech, Vol. 20, No. 5,
  900-905 (2002).
• 6 M.F. Yanik, S. Fan, Stopping light all
  optically, Phys. Rev. Lett. 92, 083901, (2004).
• 7 P. Chak, R. Iyer, J. S. Aitchison, and J. E.
  Sipe, Hamiltonian formulation of coupled-mode
  theory in waveguide structures, submitted to
  Phys. Rev. E. (2005).
• 8 MODE Solutions software package from
  Lumerical Solutions Inc. Suite 660 - 789 West
  Pender Street, Vancouver, British Columbia,
  Canada, V6C 1H2.. www.lumerical.com.

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• For the RING gap,
• the vg ? 0 and GVD ? min at band edge
• Slowing and stopping light possible
• III-V SCISSOR structures are difficult to
  fabricate due to sub-micron feature sizes