Control of energy density inside disordered medium by coupling to open or closed channels

TL;DR

This paper demonstrates an on-chip method to control light energy distribution inside a disordered medium by selectively coupling to open or closed channels, significantly altering energy density profiles and storage.

Contribution

It introduces an adaptive wavefront shaping technique on-chip to manipulate energy density distribution in disordered systems by coupling to specific channels.

Findings

Energy storage increased by 7.4 times

Energy density profile changed from exponential to peaked

On-chip platform enables precise control of light in turbid media

Abstract

We demonstrate experimentally an efficient control of light intensity distribution inside a random scattering system. The adaptive wavefront shaping technique is applied to a silicon waveguide containing scattering nanostructures, and the on-chip coupling scheme enables access to all input spatial modes. By selectively coupling the incident light to open or closed channels of the disordered system, we not only vary the total energy stored inside the system by 7.4 times, but also change the energy density distribution from an exponential decay to a linear decay and to a profile peaked near the center. This work provides an on-chip platform for controlling light-matter interactions in turbid media.