Maximum information states for coherent scattering measurements

[D. Bouchet et al., Nat. Phys., 71 (2021)]

Coherent light is a popular tool for sensing and imaging. In simple cases, one can guess or compute a spatial and/or temporal excitation beam profile that ensures that the information about a specific target can be retrieved. However, there was no general rule to find the optimal states of light that maximize the precision of a given parameter estimation. Moreover, such states are expected to depend heavily on the parameter one tries to measure. In the present paper, the authors define a general framework to identify such optimal spatial channels, regardless of the complexity of the propagating medium, using the measurement of the transmission matrix. They demonstrate this concept using wavefront shaping to probe the phase and the position of a target hidden behind a static scattering medium.

Post-doctoral positions in Ultradeep Microscopy Imaging

Colorado State University

Two post‐doctoral positions are available in the group of Randy Bartels on a two and a half year project dealing with reflection and transmission matrices in multiple-scattering media and imaging deep into tissues with nonlinear modalities.

Post-doctoral positions in Complex Nanophotonics and Novel Lasers

Yale University, Department of Applied Physics

Two post‐doctoral positions are immediately available in Professor Hui Cao's lab at Applied Physics Department of Yale University for experimental research on complex nanophotonic devices and novel lasers. The goal of this research is to harness optical nonlinearities in complex systems for photonic applications. Responsibilities include designing and fabricating photonic devices, building an optical setup, performing the experiments, and the data analysis. Familiarity with nanofabrication, numerical modeling, and wavefront shaping techniques is a plus. More information about Cao’s research program can be found at the website.

Please send your academic CV, one publication, and names/email addresses of three references to hui.cao@yale.edu.

Time reversed optical waves by arbitrary vector spatiotemporal field generation

[M. Mounaix et al., Nat. Commun., 11 (2020)]

Time-reversal allows precisely tailoring the spatio-temporal field and was originally demonstrated in acoustics. Time-reversal requires to temporally modulate the optical field independently over a large number of pixels, which is challenging in optical experiments. In the present paper, the authors developed a system allowing the modulation of the optical field spectrally and spatially over a 2d array. Harnessing this new tool, they perform a time-reversal experiment to focus and shape the optical field temporally and spatially through a multimode fiber.