Infrared spectroscopy with visible light

Journal name:
Nature Photonics
Year published:
Published online

Spectral measurements in the infrared optical range provide unique fingerprints of materials, which are useful for material analysis, environmental sensing and health diagnostics1. Current infrared spectroscopy techniques require the use of optical equipment suited for operation in the infrared range, components of which face challenges of inferior performance and high cost. Here, we develop a technique that allows spectral measurements in the infrared range using visible-spectral-range components. The technique is based on nonlinear interference of infrared and visible photons, produced via spontaneous parametric down conversion2, 3. The intensity interference pattern for a visible photon depends on the phase of an infrared photon travelling through a medium. This allows the absorption coefficient and refractive index of the medium in the infrared range to be determined from the measurements of visible photons. The technique can substitute and/or complement conventional infrared spectroscopy and refractometry techniques, as it uses well-developed components for the visible range.

At a glance


  1. Experimental set-up.
    Figure 1: Experimental set-up.

    A continuous-wave laser at 532 nm pumps two nonlinear crystals, where SPDC occurs. The crystals are placed in a vacuum chamber and CO2 is injected into the chamber. The interference pattern of the SPDC from the two crystals is imaged by a lens onto a slit of a spectrograph and recorded by a charge-coupled device (CCD) camera.

  2. Angular-wavelength intensity distribution for signal photons from two SPDC crystals.
    Figure 2: Angular-wavelength intensity distribution for signal photons from two SPDC crystals.

    a,b, Intensity distributions obtained at pressures of 20 mtorr (vacuum) (a) and 7.7 torr for CO2 gas (b). Absorption of idler photons by the CO2 leads to a shift of the fringes and a decrease in their visibility. The top axes show the corresponding wavelengths of the idler photons, which are set to be close to the CO2 resonance. Insets: angular distributions of intensity at a wavelength of signal photons of 608.5 nm (idler wavelength of 4,230 nm), denoted by yellow vertical dashed lines. In the insets, red lines show experimental data and blue dashed lines show numerical fits of the experimental data.

  3. Dependence on wavelength.
    Figure 3: Dependence on wavelength.

    a,b, Dependence of amplitude absorption coefficient (a) and refractive index (b) in the vicinity of the resonance for CO2 at a pressure of 10.5 torr. Blue squares denote experimental results and red lines theoretical calculations using HITRAN data (a) and a Kramers–Kronig relation (b). Error bars indicate ±s.d. These are estimated within the fitting procedure with equation (2) assuming a normal distribution of the intensity in the interference pattern.

  4. Dependence on pressure.
    Figure 4: Dependence on pressure.

    a,b, Dependence of amplitude absorption coefficient (a) and refractive index (b) on the pressure of CO2 at various wavelengths. In the legend in grey, detuning is indicated from the central wavelength of absorption line of 4,277 nm. Error bars indicate ±s.d. These are estimated within the fitting procedure with equation (2) assuming a normal distribution of intensity in the interference pattern.


  1. Stuart, B. H. Infrared Spectroscopy: Fundamentals and Applications (Wiley, 2004).
  2. Zou, X. Y., Wang, L. J. & Mandel, L. Induced coherence and indistinguishability in optical interference. Phys. Rev. Lett. 67, 318321 (1991).
  3. Mandel, L. Quantum effects in one-photon and two-photon interference. Rev. Mod. Phys. 71, S274S282 (1999).
  4. Gisin, N., Ribordy, G., Tittel, W. & Zbinden, H. Quantum cryptography. Rev. Mod. Phys. 74, 145195 (2002).
  5. Gisin, N. & Thew, R. Quantum communication. Nature Photon. 1, 165171 (2007).
  6. Knill, E., Laflamme, R. & Milburn, G. J. A scheme for efficient quantum computation with linear optics. Nature 409, 4652 (2001).
  7. Ladd, T. D. et al. Quantum computers. Nature 464, 4553 (2010).
  8. Giovannetti, V., Lloyd, S. & Maccone, L. Advances in quantum metrology. Nature Photon. 5, 222229 (2013).
  9. Abadie, J. et al. A gravitational wave observatory operating beyond the quantum shot-noise limit. Nature Phys. 7, 962965 (2011).
  10. Klyshko, D. N. Photon and Nonlinear Optics (Gordon & Breach Science, 1988).
  11. Burlakov, A. V. et al. Interference effects in spontaneous two-photon parametric scattering from two macroscopic regions. Phys. Rev. A 56, 32143225 (1997).
  12. Korystov, D. Y., Kulik, S. P. & Penin, A. N. Rozhdestvenski hooks in two-photon parametric light scattering. J. Exp. Theor. Phys. Lett. 73, 214218 (2001).
  13. Kulik, S. P. et al. Two-photon interference in the presence of absorption. J. Exp. Theor. Phys. 98, 3138 (2004).
  14. Lemos, G. B. et al. Quantum imaging with undetected photons. Nature 512, 409412 (2014).
  15. Hudelist, F. et al. Quantum metrology with parametric amplifier-based photon correlation interferometers. Nature Commun. 5, 3049 (2014).
  16. Chen, B. et al. Atom–light hybrid interferometer. Phys. Rev. Lett. 115, 043602 (2015).
  17. Polivanov, Y. N. Raman scattering of light by polariton. Sov. Phys. Usp. 21, 805831 (1978).
  18. Heilweil, E. J. Ultrashort-pulse multichannel infrared spectroscopy using broadband frequency conversion in LiIO3. Opt. Lett. 14, 551553 (1989).
  19. Dougherty, T. P. & Heilwell, E. J. Dual-beam subpicosecond broadband infrared spectrometer. Opt. Lett. 19, 129131 (1994).
  20. Klyshko, D. N. Ramsey interference in two-photon parametric scattering. J. Exp. Theor. Phys. 77, 222226 (1993).
  21. Belinsky, A. V. & Klyshko, D. N. Interference of classical and non-classical light. Phys. Lett. A 166, 303307 (1992).
  22. Bideau-Mehu, A., Guern, Y., Abjean, R. & Johannin-Gilles, A. Interferometric determination of the refractive index of carbon dioxide in ultraviolet region. Opt. Commun. 9, 432434 (1973).
  23. Heineken, F. W. & Battaglia, A. Absorption and refraction of ammonia as a function of pressure at 6 mm wavelength. Physica 24, 589603 (1958).
  24. Burch, D. E. & Williams, D. Total absorptance by nitrous oxide bands in the infrared. Appl. Opt. 1, 473482 (1962).
  25. Tonouchi, M. Cutting-edge terahertz technology. Nature Photon. 1, 97105 (2007).
  26. Kailash, C. J., Covert, P. A. & Hore, D. K. Phase measurement in nondegenerate three-wave mixing spectroscopy. J. Chem. Phys. 134, 044712 (2011).

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Author information


  1. Data Storage Institute, Agency for Science, Technology and Research (A*STAR), Singapore 138634, Singapore

    • Dmitry A. Kalashnikov,
    • Anna V. Paterova &
    • Leonid A. Krivitsky
  2. Department of Physics, M.V. Lomonosov Moscow State University, Moscow 119991, Russia

    • Sergei P. Kulik


D.A.K. and L.A.K. assembled the experimental set-up and conducted the measurements. A.V.P. analysed the data and carried out numerical simulations. L.A.K. and S.P.K. conceived the idea and designed the experiment. All authors contributed to preparation of the manuscript.

Competing financial interests

A.V.P., D.A.K. and L.A.K. are listed as inventors for a provisional patent application on the method described in Supplementary Section 1.

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