Applied Physics A

, Volume 95, Issue 4, pp 1101–1109

Towards athermal optically-interconnected computing system using slotted silicon microring resonators and RF-photonic comb generation

Authors

    • Department of Electrical and Computer EngineeringUniversity of California
  • Ken Kashiwagi
    • Department of Electronic Engineering, Graduate School of EngineeringUniversity of Tokyo
  • Katsunari Okamoto
    • Department of Electrical and Computer EngineeringUniversity of California
  • R. P. Scott
    • Department of Electrical and Computer EngineeringUniversity of California
  • N. K. Fontaine
    • Department of Electrical and Computer EngineeringUniversity of California
  • Dan Ding
    • Department of Electrical and Computer EngineeringUniversity of California
  • Venkatesh Akella
    • Department of Electrical and Computer EngineeringUniversity of California
  • S. J. B. Yoo
    • Department of Electrical and Computer EngineeringUniversity of California
Open AccessArticle

DOI: 10.1007/s00339-009-5120-7

Cite this article as:
Zhou, L., Kashiwagi, K., Okamoto, K. et al. Appl. Phys. A (2009) 95: 1101. doi:10.1007/s00339-009-5120-7

Abstract

We report that completely athermal design of a slotted silicon waveguide is possible by combining the negative thermo-optic (TO) coefficient of, for example, polymethyl methacrylate (PMMA) with the positive TO coefficient of silicon. When used in a microring resonator structure, the filled overcladding slotted waveguide and the unfilled (air-filled) overcladding slotted waveguide can both achieve athermal characteristics. Simulations indicate a wide range of realizations with proper design parameters of the slotted waveguides, namely, the silicon strip and slot widths. Preliminary experimental results on fabricated devices demonstrate that the temperature dependence is reduced from 91 pm/°C for a regular microring resonator to 52 pm/°C for the PMMA-clad microring resonator. Completely athermal realization is expectable in similar devices with improved fabrication techniques. For the external optical source, we demonstrate a stable 3.5 THz wide (175 modes×20 GHz) optical comb source with nearly flat spectral phase. Adjustable mode spacing and wavelength tunability across the C-band are maintained so that comb lines can be matched to the specified wavelength grid of the computing system. With such schemes, temperature controls of individual optical components in the optically interconnected computing chips become unnecessary, greatly reducing the complexity of the computing system.

PACS

42.82.Ds42.79.Ta42.72.Ai
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Copyright information

© The Author(s) 2009