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Light speckles having a conversation

Date:
October 20, 2016
Source:
University of Twente
Summary:
The amount of light passing through an opaque layer, can be enhanced using smart techniques. At the same time, the amount of reflected light diminishes, researchers show. It’s as if light speckles have a conversation of their own.
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Enhanced light pattern observed in study.
Credit: Image courtesy of University of Twente

The amount of light passing through an opaque layer, can be enhanced using smart techniques. At the same time, the amount of reflected light diminishes, researchers of the University of Twente show in their publication in Physical Review A. It's as if light speckles have a conversation of their own.

The UT scientists, publishing their new findings in Physical Review A, previously developed a technique for sending light through highly scattering substances like paint or biological tissue. Under normal circumstances, light barely passes because it is internally reflected many times, by the numerous nano particles of the material. Shaping the incident light in a smart way, it will find its way to the 'exit'. This technique, called wavefront shaping, already has a huge impact on optics and already was in the top 10 of most promising new developments of the American Institute of Physics.

Suppressed reflection

Using the technique, a pattern of bright and less bright speckles appear. Enhancing the intensity of one single speckle, has an effect on the surrounding area, research now shows: the surrounding area also has an enhanced intensity. At the same time, the amount of light that is reflected -- that leaves the material on the other side -- diminishes. Inside the layer an energy redistribution seems to take place, as if the transmitted and reflected light speckles talk to each other.

First experimental proof

The next interesting question is: will reflection be suppressed in a wide area? Or exclusively in the area in which the intensity of transmitted light is higher, around that single enhanced speckle? The remarkable result is that reflection only diminishes in the area optimized by wavefront shaping. This implies a new type of correlation between transmitted and reflected light. A recent publication predicted this correlation, but the UT scientists now experimentally prove it for the first time.

This new knowledge can lead to better energy harvesting using solar cells: with less reflection and more transmission, the efficiency can be improved. Light manipulation can also be used in very secure optical communication. In medical imaging, sharper images are possible even through opaque tissue.


Story Source:

Materials provided by University of Twente. Note: Content may be edited for style and length.


Journal Reference:

  1. Oluwafemi S. Ojambati, John T. Hosmer-Quint, Klaas-Jan Gorter, Allard P. Mosk, Willem L. Vos. Controlling the intensity of light in large areas at the interfaces of a scattering medium. Physical Review A, 2016; 94 (4) DOI: 10.1103/PhysRevA.94.043834

Cite This Page:

University of Twente. "Light speckles having a conversation." ScienceDaily. ScienceDaily, 20 October 2016. <www.sciencedaily.com/releases/2016/10/161020092122.htm>.
University of Twente. (2016, October 20). Light speckles having a conversation. ScienceDaily. Retrieved May 23, 2017 from www.sciencedaily.com/releases/2016/10/161020092122.htm
University of Twente. "Light speckles having a conversation." ScienceDaily. www.sciencedaily.com/releases/2016/10/161020092122.htm (accessed May 23, 2017).

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