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Micrometre-scale silicon electro-optic modulator

Nature volume 435, pages 325–327 (2005)Cite this article

Abstract

Metal interconnections are expected to become the limiting factor for the performance of electronic systems as transistors continue to shrink in size. Replacing them by optical interconnections, at different levels ranging from rack-to-rack down to chip-to-chip and intra-chip interconnections, could provide the low power dissipation, low latencies and high bandwidths that are needed1,2,3,4. The implementation of optical interconnections relies on the development of micro-optical devices that are integrated with the microelectronics on chips. Recent demonstrations of silicon low-loss waveguides5,6,7, light emitters8, amplifiers9,10,11 and lasers12,13 approach this goal, but a small silicon electro-optic modulator with a size small enough for chip-scale integration has not yet been demonstrated. Here we experimentally demonstrate a high-speed electro-optical modulator in compact silicon structures. The modulator is based on a resonant light-confining structure that enhances the sensitivity of light to small changes in refractive index of the silicon and also enables high-speed operation. The modulator is 12 micrometres in diameter, three orders of magnitude smaller than previously demonstrated. Electro-optic modulators are one of the most critical components in optoelectronic integration, and decreasing their size may enable novel chip architectures.

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Figure 1: Schematic layout of the ring resonator-based modulator.
Figure 2: SEM and microscope images of the fabricated device.
Figure 3: DC measurement of the ring resonator.
Figure 4: Waveforms of the electrical driving signal and the transmitted optical signal.

References

  1. Miller, D. A. B. Optical interconnects to silicon. IEEE J. Sel. Top. Quant. Electron. 6, 1312–1317 (2000)

    Article  ADS  CAS  Google Scholar 

  2. Meindl, J. D. et al. Interconnect opportunities for gigascale integration. IBM Res. Dev. 46, 245–263 (2002)

    Article  Google Scholar 

  3. Mohammed, E. M. et al. Optical I/O technology for digital VLSI. Proc. SPIE 5358, 60–70 (2004)

    Article  ADS  Google Scholar 

  4. Kibar, O., Van Blerkom, D. A., Fan, C. & Esener, S. C. Power minimization and technology comparisons for digital free-space optoelectronic interconnections. J. Lightwave Technol. 17, 546–555 (1999)

    Article  ADS  Google Scholar 

  5. Lee, K. K., Lim, D. R. & Kimerling, L. C. Fabrication of ultralow-loss Si/SiO2 waveguides by roughness reduction. Opt. Lett. 26, 1888–1890 (2001)

    Article  ADS  CAS  Google Scholar 

  6. Vlasov, Y. A. & McNab, S. J. Losses in single-mode silicon-on-insulator strip waveguides and bends. Opt. Express 12, 1622–1631 (2004)

    Article  ADS  Google Scholar 

  7. Dumon, P. et al. Low-loss SOI photonic wires and ring resonators fabricated with deep UV lithography. IEEE Photon. Technol. Lett. 16, 1328–1330 (2004)

    Article  ADS  Google Scholar 

  8. Chan, S. & Fauchet, P. M. Silicon microcavity light emitting devices. Opt. Mater. 17, 31–34 (2001)

    Article  ADS  CAS  Google Scholar 

  9. Jones, R. et al. Net continuous wave optical gain in a low loss silicon-on-insulator waveguide by stimulated Raman scattering. Opt. Express 13, 519–525 (2005)

    Article  ADS  Google Scholar 

  10. Espinola, R. L., Dadap, J. I., Osgood, R. M., McNab, S. J. & Vlasov, Y. A. Raman amplification in ultrasmall silicon-on-insulator wire waveguides. Opt. Express 12, 3713–3718 (2004)

    Article  ADS  Google Scholar 

  11. Xu, Q., Almeida, V. R. & Lipson, M. Time-resolved study of Raman gain in highly confined silicon-on-insulator waveguides. Opt. Express 12, 4437–4442 (2004)

    Article  ADS  Google Scholar 

  12. Boyraz, O. & Jalai, B. Demonstration of a silicon Raman laser. Opt. Express 12, 5269–5273 (2004)

    Article  ADS  CAS  Google Scholar 

  13. Rong, H. et al. An all-silicon Raman laser. Nature 433, 292–294 (2005)

    Article  ADS  CAS  Google Scholar 

  14. Sadagopan, T., Choi, S. J., Dapkus, P. D. & Bond, A. E. Digest of the LEOS Summer Topical Meetings MC2–3 (IEEE, Piscataway, New Jersey, 2004)

    Google Scholar 

  15. Tang, C. K. & Reed, G. T. Highly efficient optical phase modulator in SOI waveguides. Electron. Lett. 31, 451–452 (1995)

    Article  Google Scholar 

  16. Dainesi, P. et al. CMOS compatible fully integrated Mach–Zehnder interferometer in SOI technology. IEEE Photon. Technol. Lett. 12, 660–662 (2000)

    Article  ADS  Google Scholar 

  17. Liu, A. et al. A high-speed silicon optical modulator based on a metal-oxide-semiconductor capacitor. Nature 427, 615–618 (2004)

    Article  ADS  CAS  Google Scholar 

  18. Soref, R. A. & Bennett, B. R. Electrooptical effects in silicon. IEEE J. Quant. Electron. 23, 123–129 (1987)

    Article  ADS  Google Scholar 

  19. Gan, F. & Kärtner, F. X. High-speed silicon electro-optic modulator design. IEEE Photon. Technol. Lett. (in the press)

  20. Sciuto, A., Libertino, S., Alessandria, A., Coffa, S. & Coppola, G. Design, fabrication, and testing of an integrated Si-based light modulator. J. Lightwave Technol. 21, 228–235 (2003)

    Article  ADS  CAS  Google Scholar 

  21. Heebner, J. E. et al. Enhanced linear and nonlinear optical phase response of AlGaAs microring resonators. Opt. Lett. 29, 769–771 (2004)

    Article  ADS  Google Scholar 

  22. Maune, B., Lawson, R., Gunn, C., Scherer, A. & Dalton, L. Electrically tunable ring resonators incorporating nematic liquid crystals as cladding layers. Appl. Phys. Lett. 83, 4689–4691 (2003)

    Article  ADS  CAS  Google Scholar 

  23. Almeida, V. R., Barrios, C. A., Panepucci, R. R. & Lipson, M. All-optical control of light on a silicon chip. Nature 431, 1081–1084 (2004)

    Article  ADS  CAS  Google Scholar 

  24. Pradhan, S., Almeida, V. R., Barrios, C. & Lipson, M. Optical Amplifiers and Their Applications / Integrated Photonics Research Topical Meetings IWA5 CD-ROM (The Optical Society of America, Washington, DC, 2004)

    Google Scholar 

  25. Little, B. E. et al. Ultra-compact Si-SiO2 microring resonator optical channel dropping filters. IEEE Photon. Technol. Lett. 10, 549–551 (1998)

    Article  ADS  MathSciNet  Google Scholar 

  26. Barrios, C. A., Almeida, V. R., Panepucci, R. & Lipson, M. Electrooptic modulation of silicon-on-insulator submicrometer-size waveguide devices modulator. J. Lightwave Technol. 21, 2232–2239 (2003)

    Google Scholar 

  27. Almeida, V. R., Panepucci, R. R. & Lipson, M. Nanotaper for compact mode conversion. Opt. Lett. 28, 1302–1304 (2003)

    Article  ADS  CAS  Google Scholar 

  28. Muller, J. Thin silicon film p-i-n photodiodes with internal reflection. IEEE J. Solid-State Circ. 13, 173–179 (1978)

    Article  ADS  Google Scholar 

  29. Faith, T. J., Irven, R. S., Plante, S. K. & O'Neill, J. J. Contact resistance: Al and Al-Si to diffused N + and P + silicon. J. Vac. Sci. Technol. A 1, 443–448 (1983)

    Article  ADS  CAS  Google Scholar 

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Acknowledgements

This work has been partially carried out as part of the Interconnect Focus Center Research Program at Cornell University, supported in part by the Microelectronics Advanced Research Corporation (MARCO), its participating companies, and DARPA. We acknowledge support by the National Science Foundation (NSF). We thank G. Pomrenke, AFOSR, for supporting the work. We also acknowledge support by the Cornell Center for Nanoscale Systems. The devices were fabricated at the Cornell Nano-Scale Science & Technology Facility. We also thank J. Shah, DARPA, for funding this work as part of the EPIC programme.

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  1. School of Electrical and Computer Engineering, Cornell University, 411 Phillips Hall, Ithaca, New York, 14853, USA

    Qianfan Xu, Bradley Schmidt, Sameer Pradhan & Michal Lipson

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  1. Qianfan Xu
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  2. Bradley Schmidt
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  3. Sameer Pradhan
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Correspondence to Michal Lipson.

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Xu, Q., Schmidt, B., Pradhan, S. et al. Micrometre-scale silicon electro-optic modulator. Nature 435, 325–327 (2005). https://doi.org/10.1038/nature03569

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