Nanoscale Electro-Optic Modulator

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Technology Description


This technology strays from traditional transparent conductive oxide modulators, providing nano-cavity modulators on strip waveguides instead of using straight waveguide modulators. Photonic crystal mirror segments are placed adjacent to the photonic crystal nano-cavity. The nano-cavity also contains a metal-oxide semiconductor capacitor and the air holes in the photonic crystal mirror segments can be tuned to allow the modulator to operate in various wavelengths. The active region of the device will be free from metals, utilizing a TCO gate. It also operates in the dual mode of cavity resonance and optical absorption by exploiting the refractive index modulation from both the conductive oxide and the silicon waveguide. Manufacturing of this device leads to a modulator many times smaller than traditional modulators, operating at improved energy efficiencies.


Features & Benefits

  • Ultra-compact device footprint and modulation volume
  • Active region is metal-free and low loss
  • Compatible with existing CMOS processes




  • Silicon electro-optic modulators
  • On-chip optical interconnects


Background of Invention


Silicon photonics have great potential to transform future optical interconnect systems by reducing energy consumption and improving bandwidth by orders of magnitude. However, silicon photonic devices remain limited by a relatively weak plasma dispersion effect and diffraction limit, leading to large losses. To compensate for this drawback, some modulators incorporate transparent conductive oxides into straight silicon waveguides or plasmonic slot waveguides which requires a long modulation length to induce sufficient absorption. This technology provides a silicon-TCO nano-cavity modulator instead of a straight waveguide modulator. Due to the ultra-compact nature of the modulator, this device has reported the smallest active modulation region to date, leading to improved energy efficiencies. The active region of the device is also free of metals, offering a low device loss, high Q-factors, and better compatibility with complementary metal-oxide-semiconductor processes.




Patent pending


Patent Information:
For Information, Contact:
David Dickson
IP & Licensing Manager
Oregon State University
Alan Wang
Erwen Li
Optical Modulator
Photonic Crystal Cavity
Photonic devices
Silicon Photonics
Transparent Conductive Oxides
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