Weinberg, Gil, Elad Sunray, and Ori Katz. “
Noninvasive megapixel fluorescence microscopy through scattering layers by a virtual incoherent reflection matrix”.
Science Advances 10.47 (2024): ,
10, 47, eadl5218. Web.
Publisher's VersionAbstractOptical-resolution fluorescence imaging through and within complex samples presents a major challenge due to random light scattering, with substantial implications across multiple fields. While considerable advancements in coherent imaging through severe multiple scattering have been recently introduced by reflection matrix processing, approaches that tackle scattering in incoherent fluorescence imaging have been limited to sparse targets, require high-resolution control of the illumination or detection wavefronts, or require a very large number of measurements. Here, we present an approach that allows the adaptation of well-established reflection matrix techniques to scattering compensation in incoherent fluorescence imaging. We experimentally demonstrate that a small number of conventional wide-field fluorescence microscope images acquired under unknown random illuminations can effectively be used to construct a virtual fluorescence-based reflection matrix. Processing this matrix by an adapted matrix-based scattering compensation algorithm allows reconstructing megapixel-scale images from <150 acquired frames, without any spatial light modulators or computationally intensive processing. Fluorescence microscopy images that have been distorted by scattering are computationally corrected by a matrix-based approach.
Sunray, Elad, et al. “
Beyond memory-effect matrix-based imaging in scattering media by acousto-optic gating”.
APL Photonics 99 (2024). Web.
Publisher's VersionAbstractImaging inside scattering media at optical resolution is a longstanding challenge affecting multiple fields, from bio-medicine to astronomy. In recent years, several groundbreaking techniques for imaging inside scattering media, in particular scattering-matrix-based approaches, have shown great promise. However, due to their reliance on the optical “memory-effect,” these techniques usually suffer from a restricted field of view. Here, we demonstrate that diffraction-limited imaging beyond the optical memory-effect can be robustly achieved by combining acousto-optic spatial-gating with state-of-the-art matrix-based imaging techniques. In particular, we show that this can be achieved by computational processing of scattered light fields captured under scanned acousto-optic modulation. The approach can be directly utilized whenever the ultrasound focus size is of the order of the memory-effect range, independently of the scattering angle.
Hörner, Helmut, et al. “
Coherent Perfect Absorption of Arbitrary Wavefronts at an Exceptional Point”.
Physical Review Letters 133.17 (2024): ,
133, 17, 173801. Web.
Publisher's VersionAbstractA coherent perfect absorber exploits the interferometric nature of light to deposit all of a light field’s incident energy into an otherwise weakly absorbing sample. The downside of this concept is that the necessary destructive interference in coherent perfect absorbers gets easily destroyed both by spectrally or spatially detuning the incoming light field. Each of these two limitations has recently been overcome by insights from exceptional-point physics and by using a degenerate cavity, respectively. Here, we show how these two concepts can be combined into a new type of cavity design, which allows broadband exceptional-point absorption of arbitrary wavefronts. We present two possible implementations of such a massively degenerate exceptional-point absorber and compare analytical results with numerical simulations.
Slobodkin, Yevgeny, and Ori Katz. “
Computational wave-based photoacoustic imaging through an unknown thick aberrating layer”.
Photoacoustics 36.2213-5979 (2024): ,
36, 2213-5979, 100584. Web.
Publisher's VersionAbstractWe introduce a physics-based computational reconstruction framework for non-invasive photoacoustic tomography through a thick aberrating layer. Our wave-based approach leverages an analytic formulation of diffraction to beamform a photoacoustic image, when the aberrating layer profile is known. When the profile of the aberrating layer is unknown, the same analytical formulation serves as the basis for an automatic-differentiation regularized optimization algorithm that simultaneously reconstructs both the profile of the aberrating layer and the optically absorbing targets. Results from numerical studies and proof-of-concept experiments show promise for fast beamforming that takes into account diffraction effect occurring in the propagation through thick, highly-aberrating layers.