Created by sebastien.popoff on 21/05/2017

Talks Wavefront shaping

Wavefront Shaping in Complex Media:
From the Compensation to the Exploitation of Randomness

Sebastien M. Popoff

CLEO 2017 - San Jose, CA (USA), May 16 2017

Abstract: In the past ten years, many techniques were developed to control light propagation in complex transmission media using spatial light modulators. It involved applications in numerous fields including biomedical imaging and therapy, fiber endoscopy, cryptography, optical micromanipulation, optical spectroscopy, telecommunications and random lasers and also served as a tool for fundamental studies of light propagation in complex environments.

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Created by sebastien.popoff on 20/07/2013

Talks Wavefront shaping

 

Wavefront shaping: Controlling light in disordered materials

ANP2010 - Elbert van Putten
2010


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Created by sebastien.popoff on 16/07/2013

Talks Wavefront shaping

Spatio-temporal control of light in complex media

PhD defense Sébastien Popoff

December 14th 2011


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Created by sebastien.popoff on 14/06/2013

Highlights

A noninvasive measure of the transmission matrix in scattering media using the photo-acoustic effect

[T. Chaigne et al., Nat. Photon., 8, (2013)]

Optical wavefront shaping allows imaging or focusing of light in strongly scattering media at a depth where usual microscopy techniques fail. However, wavefront shaping techniques usually require captors (like a CCD array) or probes (like fluorescent entities) to guide the focusing of light or to characterize the system for imaging purposes. Recently, [X. Xu, H. Liu and L.V. Wang, Nat. Photon., 5, 154, (2011)] and [X. Xu, H. Liu and L.V. Wang, Nat. Photon., 7, 300, (2013)]  (see Retrieving an optical scale resolution with light focusing guided by ultrasound) have shown how to use ultrasound to noninvasively guide light focusing in a scattering medium. This method uses an iterative optimization scheme for focusing on each target. This limits the applications for imaging due to the time requirements. In this paper, the authors use the photo-acoustic effect to measure the transmission matrix that links the optical field on the surface of a spatial light modulator (SLM) modulating the input light to the optical field on different points inside a scattering medium. This knowledge of this matrix allows selective focusing on multiple points and detection of targets buried in the medium.

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