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Efficient low-loss InGaAsP/Si hybrid MOS optical modulator

Abstract

An optical modulator integrated on silicon is a key enabler for high-performance optical interconnects1,2,3,4,5,6. However, Si-based optical modulators suffer from low phase-modulation efficiency owing to the weak plasma dispersion effect in Si, which also results in large optical loss. Therefore, it is essential to find a novel modulation scheme for Si photonics. Here, we demonstrate an InGaAsP/Si hybrid metal-oxide–semiconductor (MOS) optical modulator formed by direct wafer bonding7,8. Electron accumulation at the InGaAsP MOS interface enables the utilization of the electron-induced refractive index change in InGaAsP, which is significantly greater than that in Si (refs 9,10). The presented modulator exhibits a phase-modulation efficiency of 0.047 Vcm and low optical attenuation of 0.23 dB at π phase shift at 1.55 μm wavelength, which are approximately 5 times higher and 10 times lower than Si MOS optical modulators11,12,13,14,15,16,17, respectively. This approach provides a new, high-performance phase-modulation scheme for Si photonics.

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Figure 1: Schematics and images of an InGaAsP/Si hybrid MOS optical modulator.
Figure 2: Numerical analysis of an InGaAsP/Si hybrid MOS optical modulator.
Figure 3: Measurement of an InGaAsP/Si hybrid MOS optical modulator.
Figure 4: Benchmarks of the modulation efficiency and loss for an InGaAsP/Si hybrid MOS optical modulator.
Figure 5: Benchmarks of the modulation bandwidth for an InGaAsP/Si hybrid MOS optical modulator.

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References

  1. Reed, G. T., Mashanovich, G., Gardes, F. Y. & Thomson, D. J. Silicon optical modulators. Nat. Photon. 4, 518–526 (2010).

    Article  ADS  Google Scholar 

  2. Kuo, Y.-H. et al. Strong quantum-confined Stark effect in germanium quantum-well structures on silicon. Nature 437, 1334–1336 (2005).

    Article  ADS  Google Scholar 

  3. Jacobsen, R. S. et al. Strained silicon as a new electro-optic material. Nature 441, 199–202 (2006).

    Article  ADS  Google Scholar 

  4. Liu, J. et al. Waveguide-integrated, ultralow-energy GeSi electro-absorption modulators. Nat. Photon. 2, 433–437 (2008).

    Article  Google Scholar 

  5. Kim, Y., Takenaka, M., Osada, T., Hata, M. & Takagi, S. Strain-induced enhancement of plasma dispersion effect and free-carrier absorption in SiGe optical modulators. Sci. Rep. 4, 4683 (2014).

    Article  ADS  Google Scholar 

  6. Sun, C. et al. Single-chip microprocessor that communicates directly using light. Nature 528, 534–538 (2015).

    Article  ADS  Google Scholar 

  7. Han, J.-H., Takenaka, M. & Takagi, S. Study on void reduction in direct wafer bonding using Al2O3/HfO2 bonding interface for high-performance Si high-k MOS optical modulators. Jpn. J. Appl. Phys. 55, 04EC06 (2016).

    Article  Google Scholar 

  8. Han, J.-H., Takenaka, M. & Takagi, S. Extremely high modulation efficiency III-V/Si hybrid MOS optical modulator fabricated by direct wafer bonding. In Int. Electron. Dev. Meeting 25.5 (IEEE, 2016).

  9. Bennett, B. R., Soref, R. A. & Del Alamo, J. A. Carrier-induced change in refractive index of InP, GaAs, and InGaAsP. IEEE J. Quantum Electron. 26, 113–122 (1990).

    Article  ADS  Google Scholar 

  10. Weber, J.-P. Optimization of the carrier-induced effective index change in InGaAsP waveguides—application to tunable Bragg filters. IEEE J. Quantum Electron. 30, 1801–1816 (1994).

    Article  ADS  Google Scholar 

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

    Article  ADS  Google Scholar 

  12. Liao, L. et al. High speed silicon Mach-Zehnder modulator. Opt. Express 13, 3129–3135 (2005).

    Article  ADS  Google Scholar 

  13. Webster, M. et al. An efficient MOS-capacitor based silicon modulator and CMOS drivers for optical transmitters. In Int. Conf. Group IV Photonics WB1 (IEEE, 2014).

  14. Webster, M. et al. Silicon photonic modulator based on a MOS-capacitor and a CMOS Driver. In Compound Semiconductor Integrated Circuit Symp. E.3 (IEEE, 2014).

  15. Campenhout, J. V. et al. Low-voltage, low-loss, multi-Gb/s silicon micro-ring modulator based on a MOS capacitor. In Optical Fiber Commun. Conf. Exhibition OM2E.4 (OSA, 2012).

  16. Fujikata, J., Takahashi, M., Takahashi, S., Horikawa, T. & Nakamura, T. High-speed and high-efficiency Si optical modulator with MOS junction, using solid-phase crystallization of polycrystalline silicon. Jpn. J. Appl. Phys. 55, 042202 (2016).

    Article  ADS  Google Scholar 

  17. Fujikata, J. et al. High-performance MOS-capacitor-type Si optical modulator and surface-illumination-type Ge photodetector for optical interconnection. Jpn. J. Appl. Phys. 55, 04EC01 (2016).

    Article  Google Scholar 

  18. Soref, R. The past, present, and future of silicon photonics. IEEE J. Sel. Top. Quantum Electron. 12, 1678–1686 (2006).

    Article  ADS  Google Scholar 

  19. Beausoleil, R. G., McLaren, M. & Jouppi, N. P. Photonic architectures for high-performance data centers. IEEE J. Sel. Top. Quantum Electron. 19, 3700109 (2013).

    Article  ADS  Google Scholar 

  20. Taubenblatt, M. A. Optical interconnects for high-performance computing. J. Lightwave Technol. 30, 448–457 (2012).

    Article  ADS  Google Scholar 

  21. Reed, G. T. et al. High-speed carrier-depletion silicon Mach-Zehnder optical modulators with lateral PN junctions. Front. Phys. 2, 77 (2014).

    Article  Google Scholar 

  22. Akiyama, S. & Usuki, T. High-speed and efficient silicon modulator based on forward-biased pin diodes. Front. Phys. 2, 65 (2014).

    Article  Google Scholar 

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

    Article  ADS  Google Scholar 

  24. Han, J.-H., Takenaka, M. & Takagi, S. Feasibility study of III-V/Si hybrid MOS optical modulators consisting of n-InGaAsP/Al2O3/p-Si MOS capacitor formed by wafer bonding. In Int. Conf. Group IV Photonics ThP16 (IEEE, 2016).

  25. Duan, G. H. et al. New advances on heterogeneous integration of III–V on silicon. J. Lightwave Technol. 33, 976–983 (2015).

    Article  ADS  Google Scholar 

  26. Liang, D., Huang, X., Kurczveil, G., Fiorentino, M. & Beausoleil, R. G. Integrated finely tunable microring laser on silicon. Nat. Photon. 10, 719–722 (2016).

    Article  ADS  Google Scholar 

  27. Botteldooren, D. & Baets, R. Influence of band-gap shrinkage on the carrier-induced refractive index change in InGaAsP. Appl. Phys. Lett. 54, 1989–1991 (1989).

    Article  Google Scholar 

  28. Adachi, S. Material parameters of In1−xGaxAsyP1−y and related binaries. J. Appl. Phys. 53, 8775–8792 (1982).

    Google Scholar 

  29. Sotoodeh, M., Khalid, A. H. & Rezazadeh, A. A. Empirical low-field mobility model for III–V compounds applicable in device simulation codes. J. Appl. Phys. 87, 2890–2900 (2000).

    Article  Google Scholar 

  30. Chen, H.-W., Peters, J. D. & Bowers, J. E. Forty Gb/s hybrid silicon Mach-Zehnder modulator with low chirp. Opt. Express 19, 1455–1460 (2011).

    Article  ADS  Google Scholar 

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Acknowledgements

This work was supported in part by the New Energy and Industrial Technology Development Organization (NEDO) and the Japan Society for the Promotion of Science (JSPS) KAKENHI grant number JP26709022. The authors would like to thank O. Ichikawa, M. Yokoyama, T. Yamamoto and H. Yamada in Sumitomo Chemical Corporation for their collaboration. J.-H.H. and F.B. would also like to thank JSPS for a research fellowship.

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J.-H.H. contributed to the idea, simulation, fabrication, measurement and manuscript preparation. F.B. contributed to the simulation and manuscript preparation. J.F. and S. Takahashi contributed to the measurement of the dynamic characteristics. S.Takagi contributed to the discussion and provided high-level project supervision. M.T. contributed to the idea, discussion, manuscript revision, and provided high-level project supervision.

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Correspondence to Jae-Hoon Han or Mitsuru Takenaka.

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The authors declare no competing financial interests.

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Han, JH., Boeuf, F., Fujikata, J. et al. Efficient low-loss InGaAsP/Si hybrid MOS optical modulator. Nature Photon 11, 486–490 (2017). https://doi.org/10.1038/nphoton.2017.122

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