Berlin 2024 – scientific programme

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O: Fachverband Oberflächenphysik

O 71: Poster: Plasmonics and Nanooptics

O 71.3: Poster

Wednesday, March 20, 2024, 18:00–20:00, Poster D

Control and measurement of optical fields in a random photonic media — •Diptabrata Paul and Frank Cichos — Peter Debye Institute for Soft Matter Physics, Universität Leipzig, 04103 Leipzig, Germany

The ubiquitous presence of disordered photonic structures in nature has inspired investigation of how wave propagation in complex media could be exploited to control the scattering, transport, and localization of light in matter. However, volumetric scattering in the complex media leads to a universal interference pattern called speckles, which poses a significant challenge in controlling and probing phase and amplitude of light after passing through the medium. To address this, herein, we propose a method by which modulation of incident optical fields using a digital micromirror device (DMD) could achieve modification of optical fields in the random photonic media. Real time imaging of the speckles along with an iterative feedback algorithm sequentially switches the DMD mirror states to on or off positions to achieve incident field binary amplitude modulation and hence desired modification of fields in the medium. On the other hand, we employ a diffuser that could be used for sensing the thermo-optical modulation of an optical field. Specifically, we infer the local perturbation of the wave front by comparing the speckle pattern between a reference and a thermo-optically modified field, which in turn can also quantify the temperature profile. The advent of spatial control over the phase and amplitude of light waves can lead to major advances in fields from imaging and information technology to biomedical optics.

Keywords: Complex media; thermoplasmonics