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Speckle-free laser imaging using random laser illumination

An Erratum to this article was published on 28 June 2012

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Many imaging applications require increasingly bright illumination sources, motivating the replacement of conventional thermal light sources with bright light-emitting diodes, superluminescent diodes and lasers. Despite their brightness, lasers and superluminescent diodes are poorly suited for full-field imaging applications because their high spatial coherence leads to coherent artefacts such as speckle that corrupt image formation1,2. We recently demonstrated that random lasers can be engineered to provide low spatial coherence3. Here, we exploit the low spatial coherence of specifically designed random lasers to demonstrate speckle-free full-field imaging in the setting of intense optical scattering. We quantitatively show that images generated with random laser illumination exhibit superior quality than images generated with spatially coherent illumination. By providing intense laser illumination without the drawback of coherent artefacts, random lasers are well suited for a host of full-field imaging applications from full-field microscopy4 to digital light projector systems5.

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Figure 1: Random lasers, a new kind of light source for imaging.
Figure 2: Random lasers prevent speckle formation.
Figure 3: Random lasers produce speckle-free images.
Figure 4: Random lasers prevent crosstalk during image formation.

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  • 14 June 2012

    The original received date was incorrect. This has been corrected in the HTML and PDF versions.


  1. Oliver, B. M. Sparkling spots and random diffraction. Proc. IEEE 51, 220–221 (1963).

    Article  Google Scholar 

  2. Goodman, J. W. Optical methods for suppressing speckle, in Speckle Phenomena in Optics 141–186 (Roberts & Company, 2007).

    Google Scholar 

  3. Redding, B., Choma, M. A. & Cao, H. Spatial coherence of random laser emission. Opt. Lett 36, 3404–3406 (2011).

    Article  ADS  Google Scholar 

  4. Dingel, B. & Kawata, S. Speckle-free image in a laser-diode microscope by using the optical feedback effect. Opt. Lett. 18, 549–551 (1993).

    Article  ADS  Google Scholar 

  5. Yurlov, V., Lapchuk, A., Yun, S., Song, J. & Yang, H. Speckle suppression in scanning laser display. Appl. Opt. 47, 179–187 (2008).

    Article  ADS  Google Scholar 

  6. Rigden, J. D. & Gordon, E. I. The granularity of scattered optical maser light. Proc. Inst. Radio Eng. 50, 2367–2368 (1962).

    Google Scholar 

  7. Geri, A. G. & Williams, L. A. Perceptual assessment of laser-speckle contrast. J. Soc. Inf. Displ. 20, 22–27 (2012).

    Article  Google Scholar 

  8. Gaska, J. P., Tai, C. & Geri, G. A. Laser-speckle properties and their effect on target detection J. Soc. Inf. Displ. 15, 1023–1028 (2007).

    Article  Google Scholar 

  9. Artigas, J. M., Felipe, A. & Buades, M. J. Contrast sensitivity of the visual system in speckle imagery. J. Opt. Soc. Am. A 11, 2345–2349 (1994).

    Article  ADS  Google Scholar 

  10. McKechnie, T. S. Speckle reduction, in Topics in Applied Physics Vol. 9 (ed. Dainty, J. C.) 123–170 (Springer, 1975).

    Google Scholar 

  11. Cao, H. Lasing in disordered media, in Progress in Optics Vol. 45 (ed. Wolf, E.) 317–370 (North-Holland, 2003).

    Google Scholar 

  12. Wierma, D. S. The physics and applications of random lasers. Nature Phys. 4, 359–367 (2008).

    Article  ADS  Google Scholar 

  13. Mandel, L. & Wolf, E. Optical Coherence and Quantum Optics (Cambridge Univ. Press, 1995).

    Book  Google Scholar 

  14. SugarCUBETM Red, Nathaniel Group, Vergennes, VT, USA; available at

  15. Hitzenberger, C. K., Danner, M., Drexler, W. & Fercher, A. F. Measurement of the spatial coherence of superluminescent diodes. J. Mod. Opt. 46, 1763–1774 (1999).

    Article  ADS  Google Scholar 

  16. Chesnoy, J. & Fini, L. Stabilization of a femtosecond dye laser synchronously pumped by a frequency-doubled mode-locked YAG laser. Opt. Lett. 11, 635–637 (1986).

    Article  ADS  Google Scholar 

  17. Knox, W. H. & Beisser, F. A. Two-wavelength synchronous generation of femtosecond pulses with 100-fs jitter. Opt. Lett. 17, 1012–1014 (1992).

    Article  ADS  Google Scholar 

  18. Johnson, A. M. & Simpson, W. M. Continuous-wave mode-locked Nd:YAG-pumped subpicosecond dye lasers. Opt. Lett. 8, 554–556 (1983).

    Article  ADS  Google Scholar 

  19. Seifert, F. & Petrov, V. Synchronous pumping of a visible dye laser by a frequency double mode-locked Ti:sapphire laser and its application for difference frequency generation in the near infrared. Opt. Commun. 99, 413–420 (1993).

    Article  ADS  Google Scholar 

  20. Bryan, R. N. Introduction to the Science of Medical Imaging (Cambridge Univ. Press, 2009).

    Book  Google Scholar 

  21. Kang, D. & Milster, T. D. Simulation method for non-Gaussian speckle in a partially coherent system. J. Opt. Soc. Am. A 26, 1954–1960 (2009).

    Article  ADS  Google Scholar 

  22. Kang, D. & Milster, T. D. Effect of optical aberration on Gaussian speckle in a partially coherent imaging system. J. Opt. Soc. Am. A 26, 2577–2585 (2009).

    Article  ADS  Google Scholar 

  23. Kang, D. & Milster, T. D. Effect of fractal rough-surface Hurst exponent on speckle in imaging systems. Opt. Lett. 34, 3247–3249 (2009).

    Article  ADS  Google Scholar 

  24. Cao, H. et al. Random laser action in semiconductor powder. Phys. Rev. Lett. 82, 2278–2281 (1999).

    Article  ADS  Google Scholar 

  25. Leong, E. S. P. & Yu, S. F. UV random lasing action in p-SiC(4H)/i-ZnO-SiO2 nanocomposite/n-ZnO:Al heterojunction diodes. Adv. Mater. 18, 1685–1688 (2006).

    Article  Google Scholar 

  26. Zhu, H. et al. Low-threshold electrically pumped random lasers. Adv. Mater. 22, 1877–1881 (2010).

    Article  Google Scholar 

  27. Xu, J. & Xiao, M. Lasing action in colloidal CdS/CdSe/CdS quantum wells. Appl. Phys. Lett. 87, 173117 (2005).

    Article  ADS  Google Scholar 

  28. Chu, S., Olmedo, M., Yang, Z., Kong, J. & Liu, J. Electrically pumped ultraviolet ZnO diode lasers on Si. Appl. Phys. Lett. 93, 181106 (2008).

    Article  ADS  Google Scholar 

  29. Ma, X., Chen, P., Li, D., Zhang, Y. & Yang, D. Electrically pumped ZnO film ultraviolet random lasers on silicon substrate. Appl. Phys. Lett. 91, 251109 (2007).

    Article  ADS  Google Scholar 

  30. Papadakis, V. M. et al. Single-shot temporal coherence measurements of random lasing media. J. Opt. Soc. Am. B 24, 31–36 (2007).

    Article  ADS  Google Scholar 

  31. Redding, B., Choma, M. A. & Cao, H. Spatially incoherent random lasers for full field optical coherence tomography, in Conference on Lasers and Electro-Optics, PDPC7 (Optical Society of America, 2011).

    Google Scholar 

  32. Huang, D. et al. Optical coherence tomography. Science 254, 1178–1181 (1991).

    Article  ADS  Google Scholar 

  33. Karamata, B. et al. Multiple scattering in optical coherence tomography. I. Investigation and modeling. J. Opt. Soc. Am. A 22, 1369–1379 (2005).

    Article  ADS  MathSciNet  Google Scholar 

  34. Karamata, B. et al. Multiple scattering in optical coherence tomography. II. Experimental and theoretical investigation of cross talk in wide-field optical coherence tomography. J. Opt. Soc. Am. A 22, 1380–1388 (2005).

    Article  ADS  MathSciNet  Google Scholar 

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H.C. acknowledges support from the National Science Foundation (grants ECCS-1128542 and ECCS-1068642). M.A.C. acknowledges support through a K12 award from the Yale Child Health Research Center (5K12-HD001401-12). The authors wish to thank A.D. Stone, E.R. Dufresne, L.H. Staib and H.D. Tagare for discussions and H. Noh for technical assistance.

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M.A.C and H.C. initiated the study. B.R. set up the experiments and collected all the data in the laboratory of H.C. B.R. analysed the data and prepared the manuscript. M.A.C. and H.C. contributed extensively to data interpretation and manuscript preparation.

Corresponding authors

Correspondence to Brandon Redding, Michael A. Choma or Hui Cao.

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The authors declare no competing financial interests.

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Redding, B., Choma, M. & Cao, H. Speckle-free laser imaging using random laser illumination. Nature Photon 6, 355–359 (2012).

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