Skip to main content

Thank you for visiting You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

  • Letter
  • Published:

Bridging the mid-infrared-to-telecom gap with silicon nanophotonic spectral translation


Extending beyond traditional telecom-band applications to optical interconnects1, the silicon nanophotonic integrated circuit platform also has notable advantages for use in high-performance mid-infrared optical systems operating in the 2–8 µm spectral range2,3. Such systems could find applications in industrial and environmental monitoring4, threat detection5, medical diagnostics6 and free-space communication7. Nevertheless, the advancement of chip-scale systems is impeded by the narrow-bandgap semiconductors traditionally used to detect mid-infrared photons. The cryogenic or multistage thermo-electric cooling required to suppress dark-current noise8, which is exponentially dependent on Eg/kT, can restrict the development of compact, low-power integrated mid-infrared systems. However, if the mid-infrared signals were spectrally translated to shorter wavelengths, wide-bandgap photodetectors could be used to eliminate prohibitive cooling requirements. Furthermore, such detectors typically have larger detectivity and bandwidth than their mid-infrared counterparts8. Here, we use efficient four-wave mixing in silicon nanophotonic wires9,10,11,12 to facilitate spectral translation of a signal at 2,440 nm to the telecom band at 1,620 nm, across a span of 62 THz. Furthermore, a simultaneous parametric translation gain of 19 dB can significantly boost sensitivity to weak mid-infrared signals.

This is a preview of subscription content, access via your institution

Access options

Buy this article

Prices may be subject to local taxes which are calculated during checkout

Figure 1: Structural design and transmission characteristics of the silicon nanophotonic wire spectral translation device.
Figure 2: Wavelength-resolved on-chip spectral translation efficiency and parametric signal gain.
Figure 3: Phase-matched signal and idler wavelengths linked by the silicon nanophotonic spectral translation process.

Similar content being viewed by others


  1. Green, W. M. J. et al. in SEMICON (Chiba, 2010); available at

  2. Soref, R. Mid-infrared photonics in silicon and germanium. Nature Photon. 4, 495–497 (2010).

    Article  ADS  Google Scholar 

  3. Jalali, B. et al. Prospects for silicon mid-IR Raman lasers. IEEE J. Sel. Top. Quantum Electron. 12, 1618–1627 (2006).

    Article  ADS  Google Scholar 

  4. Willer, U., Saraji, M., Khorsandi, A., Geiser, P. & Schade, W. Near- and mid-infrared laser monitoring of industrial processes, environment and security applications. Opt. Laser Eng. 44, 699–710 (2006).

    Article  Google Scholar 

  5. Moore, D. S. Instrumentation for trace detection of high explosives. Rev. Sci. Instrum. 75, 2499–2512 (2004).

    Article  ADS  Google Scholar 

  6. Namjou, K., Roller, C. B. & McCann, P. J. The Breathmeter: a new laser device to analyze your health. IEEE Circ. Dev. Magazine 22–28 (2006).

  7. Capasso, F. et al. Quantum cascade lasers: ultrahigh-speed operation, optical wireless communication, narrow linewidth, and far-infrared emission. IEEE J. Quantum Electron. 38, 511–532 (2002).

    Article  ADS  Google Scholar 

  8. Sze, S. M. Physics of Semiconductor Devices (Wiley, 1981).

    Google Scholar 

  9. Zlatanovic, S. et al. Mid-infrared wavelength conversion in silicon waveguides using ultracompact telecom-band-derived pump source. Nature Photon. 4, 561–564 (2010).

    Article  ADS  Google Scholar 

  10. Lau, R. K. W. et al. Continuous-wave mid-infrared frequency conversion in silicon nanowaveguides. Opt. Lett. 36, 1263–1265 (2011).

    Article  ADS  Google Scholar 

  11. Liu, X., Osgood, J. R. M., Vlasov, Y. A. & Green, W. M. J. Mid-infrared optical parametric amplifier using silicon nanophotonic waveguides. Nature Photon. 4, 557–560 (2010).

    Article  ADS  Google Scholar 

  12. Kuyken, B. et al. 50 dB parametric on-chip gain in silicon photonic wires. Opt. Lett. 36, 4401–4403 (2011).

    Article  ADS  Google Scholar 

  13. Midwinter, J. E. & Warner, J. Up-conversion of near infrared to visible radiation in lithium-meta-niobate. J. Appl. Phys. 38, 519–523 (1967).

    Article  ADS  Google Scholar 

  14. Buchter, K. D. F., Herrmann, H., Langrock, C., Fejer, M. M. & Sohler, W. All-optical Ti:PPLN wavelength conversion modules for free-space optical transmission links in the mid-infrared. Opt. Lett. 34, 470–472 (2009).

    Article  ADS  Google Scholar 

  15. Dam, J. S., Pedersen, C. & Tidemand-Lichtenberg, P. High-resolution two-dimensional image upconversion of incoherent light. Opt. Lett. 35, 3796–3798 (2010).

    Article  ADS  Google Scholar 

  16. Baehr-Jones, T. et al. Silicon-on-sapphire integrated waveguides for the mid-infrared. Opt. Express 18, 12127–12135 (2010).

    Article  ADS  Google Scholar 

  17. Mashanovich, G. Z. et al. Low loss silicon waveguides for the mid-infrared. Opt. Express 19, 7112–7119 (2011).

    Article  ADS  Google Scholar 

  18. Li, F. et al. Low propagation loss silicon-on-sapphire waveguides for the mid-infrared. Opt. Express 19, 15212–15220 (2011).

    Article  ADS  Google Scholar 

  19. Kuyken, B. et al. in Integrated Photonics Research, paper IMB6 (Ottawa, 2011).

  20. Spott, A., Liu, Y., Baehr-Jones, T., Ilic, R. & Hochberg, M. Silicon waveguides and ring resonators at 5.5 mm. Appl. Phys. Lett. 97, 213501 (2010).

    Article  ADS  Google Scholar 

  21. Shankar, R., Leijssen, R., Bulu, I. & Lončar, M. Mid-infrared photonic crystal cavities in silicon. Opt. Express 19, 5579–5586 (2011).

    Article  ADS  Google Scholar 

  22. Van Camp, M. A. et al. in Conference on Lasers and Electro-Optics, paper CTu3I.2 (San Jose, 2012).

  23. Lin, Q., Johnson, T. J., Perahia, R., Michael, C. P. & Painter, O. J. A proposal for highly tunable optical parametric oscillation in silicon micro-resonators. Opt. Express 16, 10596–10610 (2008).

    Article  ADS  Google Scholar 

  24. Tien, E. K. et al. Discrete parametric band conversion in silicon for mid-infrared applications. Opt. Express 18, 21981–21989 (2010).

    Article  ADS  Google Scholar 

  25. Bristow, A. D., Rotenberg, N. & van Driel, H. M. Two-photon absorption and Kerr coefficients of silicon for 850–2200 nm. Appl. Phys. Lett. 90, 191104 (2007).

    Article  ADS  Google Scholar 

  26. Huang, Y. et al. Electrical signal-to-noise ratio improvement in indirect detection of mid-IR signals by wavelength conversion in silicon-on-sapphire waveguides. Appl. Phys. Lett. 99, 181122 (2011).

    Article  ADS  Google Scholar 

  27. Zlatanovic, S. et al. Mid-infrared wavelength conversion in silicon waveguides pumped by silica-fiber-based source. IEEE J. Sel. Top. Quantum Electron. 18, 612–620 (2012).

    Article  ADS  Google Scholar 

  28. Ophir, N. et al. First demonstration of a 10-Gb/s RZ end-to-end four-wave-mixing based link at 1884 nm using silicon nanowaveguides. IEEE Photon. Technol. Lett. 24, 276–278 (2012).

    Article  ADS  Google Scholar 

  29. Roelkens, G. et al. Integration of InP/InGaAsP photodetectors onto silicon-on-insulator waveguide circuits. Opt. Express 13, 10102–10108 (2005).

    Article  ADS  Google Scholar 

  30. Assefa, S. et al. CMOS-integrated high-speed MSM germanium waveguide photodetector. Opt. Express 18, 4986–4999 (2010).

    Article  ADS  Google Scholar 

Download references


The authors thank the staff at imec (Leuven, Belgium) where the silicon nanophotonic waveguide devices were fabricated. The authors also thank Y.A. Vlasov (IBM Research) for many helpful and motivating discussions. B.K. acknowledges the Flemish Research Foundation (FWO) for a doctoral fellowship. This work was partially funded under the Methusalem ‘Smart Photonic Chips’ FP7-ERC-INSPECTRA and FP7-ERC-MIRACLE programmes.

Author information

Authors and Affiliations



X.L. and B.K. performed the numerical dispersion and phase-matching design calculations. B.K., G.R. and R.B. supervised the waveguide device fabrication process. X.L. and B.K. performed the wavelength translation experiments with guidance and supervision from W.M.J.G. All authors contributed to data analysis and writing of the manuscript.

Corresponding author

Correspondence to William M. J. Green.

Ethics declarations

Competing interests

The authors declare no competing financial interests.

Supplementary information

Supplementary information

Supplementary information (PDF 1557 kb)

Rights and permissions

Reprints and permissions

About this article

Cite this article

Liu, X., Kuyken, B., Roelkens, G. et al. Bridging the mid-infrared-to-telecom gap with silicon nanophotonic spectral translation. Nature Photon 6, 667–671 (2012).

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI:

This article is cited by


Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing