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Amplified wavelength–time transformation for real-time spectroscopy

Abstract

Real-time spectroscopy provides invaluable information about the evolution of dynamical processes, especially non-repetitive phenomena. Unfortunately, the continuous acquisition of rapidly varying spectra represents an extremely difficult challenge. One method, wavelength–time mapping, chirps the spectrum so that it can be measured using a single-shot oscilloscope1,2,3,4. Here, we demonstrate a method that overcomes a fundamental problem that has previously plagued wavelength–time spectroscopy: fine spectral resolution requires large dispersion, which is accompanied by extreme optical loss. The present technique uses an optically amplified wavelength–time transformation to beat the dispersion-loss trade-off and facilitate high-resolution, broadband, real-time applications. We show that this distributed amplification process can even be pumped by broadband noise, generating a wide gain bandwidth using a single pump source. We apply these techniques to demonstrate real-time stimulated Raman spectroscopy. Amplified wavelength–time Raman spectroscopy creates new opportunities for the study of chemical and physical dynamics in real time.

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Figure 1: Schematic of the CWEETS set-up used to measure the SRS spectrum in a silicon waveguide.
Figure 2: Single-shot SRS spectra of silicon measured with CWEETS.
Figure 3: Sequence of silicon Raman movie frames acquired in a continuous measurement using an unstable supercontinuum probe.
Figure 4: Demonstration of the amplified wavelength–time transformation in spectroscopy.

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References

  1. Kelkar, P. V., Coppinger, F., Bhushan, A. S. & Jalali, B. Time-domain optical sensing. Electron. Lett. 35, 1661–1662 (1999).

    Article  Google Scholar 

  2. Sanders, S. T. Wavelength-agile fiber laser using group-velocity dispersion of pulsed super-continua and application to broadband spectroscopy. Appl. Phys. B 75, 799–802 (2002).

    Article  ADS  Google Scholar 

  3. Chou, J., Han, Y. & Jalali, B. Time–wavelength spectroscopy for chemical sensing. IEEE Photon. Technol. Lett. 16, 1140–1142 (2004).

    Article  ADS  Google Scholar 

  4. Hult, J., Watt, R. S. & Kaminski, C. F. Dispersion measurement in optical fibers using supercontinuum pulses. J. Lightwave Technol. 25, 820–824 (2007).

    Article  ADS  Google Scholar 

  5. Tong, Y. C., Chan, L. Y. & Tsang, H. K. Fibre dispersion or pulse spectrum measurement using a sampling oscilloscope. Electron. Lett. 33, 983–985 (1997).

    Article  Google Scholar 

  6. Han, Y., Boyraz, O. & Jalali, B. Tera-sample per second real-time waveform digitizer. Appl. Phys. Lett. 87, 241116 (2005).

    Article  ADS  Google Scholar 

  7. Watt, R. S. & Hult, J. in Proc. Europ. Combustion Meeting 1–4 (Chania, Greece, 2007).

    Google Scholar 

  8. Jackson, J. D. Classical Electrodynamics 3rd edn (Wiley, New York, 1999).

    MATH  Google Scholar 

  9. (ed. Laserna, J. J.) Modern Techniques in Raman Spectroscopy (Wiley, New York, 1996).

    Google Scholar 

  10. Eckhardt, G. et al. Stimulated Raman scattering from organic liquids. Phys. Rev. Lett. 9, 455–457 (1962).

    Article  ADS  Google Scholar 

  11. Agrawal, G. P. Nonlinear Fiber Optics 3rd edn (Academic Press, San Diego, 2001).

    MATH  Google Scholar 

  12. Lallemand, P., Simova, P. & Bret, G. Pressure-induced line shift and collisional narrowing in hydrogen gas determined by stimulated Raman emission. Phys. Rev. Lett. 17, 1239–1241 (1966).

    Article  ADS  Google Scholar 

  13. Owyoung, A. Coherent Raman gain spectroscopy using CW laser sources. IEEE J. Quant. Electron. QE-14, 192–203 (1978).

    Article  ADS  Google Scholar 

  14. Wang, C.-S. Theory of stimulated Raman scattering. Phys. Rev. 182, 482–494 (1969).

    Article  ADS  Google Scholar 

  15. Kukura, P., McCamant, D. W., Yoon, S., Wandschneider, D. B. & Mathies, R. A. Structural observation of the primary isomerization of vision with femtosecond-stimulated Raman. Science 310, 1006–1009 (2005).

    Article  ADS  Google Scholar 

  16. McCamant, D. W., Kukura, P. & Mathies, R. A. Femtosecond time-resolved stimulated Raman spectroscopy: Application to the ultrafast internal conversion in β-carotene. J. Phys. Chem. A 107, 8208–8214 (2003).

    Article  Google Scholar 

  17. Yoshizawa, M., Hattori, Y. & Kobayashi, T. Femtosecond time-resolved resonance Raman gain spectroscopy in polydiacetylene. Phys. Rev. B 49, 13259–13262 (1994).

    Article  ADS  Google Scholar 

  18. Parker, J. H., Feldman, D. W. & Ashkin, M. Raman scattering by silicon and germanium. Phys. Rev. 155, 712–714 (1967).

    Article  ADS  Google Scholar 

  19. Temple, P. A. & Hathaway, C. E. Multiphonon Raman spectrum of silicon. Phys. Rev. B 7, 3685–3697 (1973).

    Article  ADS  Google Scholar 

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

    Article  ADS  Google Scholar 

  21. Rong, H. et al. A continuous-wave Raman silicon laser. Nature 433, 725–728 (2005).

    Article  ADS  Google Scholar 

  22. Claps, R., Dimitropoulos, D., Raghunathan, V., Han, Y. & Jalali, B. Observation of stimulated Raman amplification in silicon waveguides. Opt. Express 11, 1731–1739 (2003).

    Article  ADS  Google Scholar 

  23. 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 

  24. 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 

  25. Solli, D. R. & Jalali, B. in CLEO/QELS 2007 Technical Digest, CMB3, 1–2 (OSA, Washington DC, 2007).

    Google Scholar 

  26. Stolen, R. H. & Ippen, E. P. Raman gain in glass optical waveguides. Appl. Phys. Lett. 22, 276–278 (1973).

    Article  ADS  Google Scholar 

  27. Islam, M. N. Raman amplifiers for telecommunications. IEEE J. Sel. Top. Quant. Electron. 8, 548–559 (2002).

    Article  ADS  Google Scholar 

  28. Vakhshoori, D. et al. in OSA Trends in Optics and Photonics Vol. 86, OFC Conference, Technical Digest, PD47, 1–3 (OSA, Washington DC, 2003).

    Google Scholar 

  29. Keita, K., Delaye, P., Frey, R. & Roosen, G. Relative intensity noise transfer of large-bandwidth pump lasers in Raman fiber amplifiers. J. Opt. Soc. Am. B 23, 2479–2485 (2006).

    Article  ADS  MathSciNet  Google Scholar 

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Acknowledgements

We thank P. Koonath for helpful discussions.

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Correspondence to D. R. Solli.

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Solli, D., Chou, J. & Jalali, B. Amplified wavelength–time transformation for real-time spectroscopy. Nature Photon 2, 48–51 (2008). https://doi.org/10.1038/nphoton.2007.253

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