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Optics Express

Optics Express

  • Editor: C. Martijn de Sterke
  • Vol. 19, Iss. 22 — Oct. 24, 2011
  • pp: 21989–22003

Vertical junction silicon microdisk modulators and switches

Michael R. Watts, William A. Zortman, Douglas C. Trotter, Ralph W. Young, and Anthony L. Lentine  »View Author Affiliations

Optics Express, Vol. 19, Issue 22, pp. 21989-22003 (2011)

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Vertical junction resonant microdisk modulators and switches have been demonstrated with exceptionally low power consumption, low-voltage operation, high-speed, and compact size. This paper reviews the progress of vertical junction microdisk modulators, provides detailed design data, and compares vertical junction performance to lateral junction performance. The use of a vertical junction maximizes the overlap of the depletion region with the optical mode thereby minimizing both the drive voltage and power consumption of a depletion-mode modulator. Further, the vertical junction enables contact to be made from the interior of the resonator and therein a hard outer wall to be formed that minimizes radiation in small diameter resonators, further reducing the capacitance and drive power of the modulator. Initial simple vertical junction modulators using depletion-mode operation demonstrated the first sub-100fJ/bit silicon modulators. With more intricate doping schemes and through the use of AC-coupled drive signals, 3.5μm diameter vertical junction microdisk modulators have recently achieved a communications efficiency of 3fJ/bit, making these modulators the smallest and lowest power modulators demonstrated to date, in any material system. Additionally, the demonstration was performed at 12.5Gb/s, required a peak-to-peak signal level of only 1V, and achieved bit-error-rates below 10−12 without requiring signal pre-emphasis. As an additional benefit to the use of interior contacts, higher-order active filters can be constructed from multiple vertical-junction modulators without interference of the electrodes. Doing so, we demonstrated second-order active high-speed bandpass switches with ~2.5ns switching speeds, and power penalties of only 0.4dB. Through the use of vertical junctions in resonant modulators, we have achieved the lowest power consumption, lowest voltage, and smallest silicon modulators demonstrated to date.

© 2011 OSA

OCIS Codes
(130.3120) Integrated optics : Integrated optics devices
(230.4110) Optical devices : Modulators
(230.5750) Optical devices : Resonators

ToC Category:
Integrated Optics

Original Manuscript: August 19, 2011
Revised Manuscript: September 25, 2011
Manuscript Accepted: September 26, 2011
Published: October 21, 2011

Michael R. Watts, William A. Zortman, Douglas C. Trotter, Ralph W. Young, and Anthony L. Lentine, "Vertical junction silicon microdisk modulators and switches," Opt. Express 19, 21989-22003 (2011)

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