Scattering of light in complex samples such as biological tissues renders most samples opaque to conventional imaging techniques, a problem of great practical importance.  However, although random, scattering is a deterministic process, and it can be undone, controlled, and even exploited by carefully shaping the input wavefront, forming the basis for the emerging field of optical wavefront-shaping^1,2, and opening the path to imaging through visually opaque samples³ and to the control of scattered ultrashort pulses⁴. Unfortunately, many demonstration of all-optical wavefront-shaping^1-4 require a localized feedback signal from the target, and thus an invasive implantation of an optical probe.

I will present some of our recent efforts in addressing this challenge^5-7. These include the use of the photoacoustic effect to focus and control light non-invasively inside a scattering medium⁵, and the use of optical nonlinearities to focus light noninvasively through scattering samples⁶. I will also show how one can surprisingly “see through” opaque samples and ‘around corners’ using nothing but a smartphone camera⁷, by exploiting the inherent correlations of scattered light, challenging the common view on diffuse scattered light as an information-less halo.

References

  [1]   A.P. Mosk et al., Nature Photonics 6, 283 (2012).

  [2]   D.S. Wiersma, Nature Photonics 7, 188 (2013).

  [3]   O. Katz et al., Nature Photonics 6, 549 (2012).

  [4]   O. Katz et al., Nature Photonics 5, 372 (2011).

  [5]   T. Chaigne, O. Katz et al. Nature Photonics 8, 58 (2014).

  [6]   O.Katz et al., Optica, 1, 3, 170-174 (2014).

  [7]   O. Katz, et al., Nature Photonics, 8, 784–790 (2014).