34 research outputs found
Hyperuniformity in amorphous speckle patterns
Hyperuniform structures possess the ability to confine and drive light,
although their fabrication is extremely challenging. Here we demonstrate that
speckle patters obtained by a superposition of randomly arranged sources of
Bessel beams can be used to generate hyperunifrom scalar fields. By exploiting
laser light tailored with a spatial filter, we experimentally produce (without
requiring any computational power) a speckle pattern possessing maxima at
locations corresponding to a hyperuniform distribution. By properly filtering
out intensity fluctuation from the same speckle pattern, it is possible to
retrieve an intensity profile satisfying the hyperuniformity requirements. Our
findings are supported by extensive numerical simulations.Comment: 13 pages, 7 figure
Beyond multi-view deconvolution for inherently-aligned fluorescence tomography
In multi-view fluorescence microscopy, each angular acquisition needs to be
aligned with care to obtain an optimal volumetric reconstruction. Here,
instead, we propose a neat protocol based on auto-correlation inversion, that
leads directly to the formation of inherently aligned tomographies. Our method
generates sharp reconstructions, with the same accuracy reachable after
sub-pixel alignment but with improved point-spread-function. The procedure can
be performed simultaneously with deconvolution further increasing the
reconstruction resolution
Spinning Pupil Aberration Measurement for anisoplanatic deconvolution
The aberrations in an optical microscope are commonly measured and corrected
at one location in the field of view, within the so-called isoplanatic patch.
Full-field correction is desirable for high-resolution imaging of large
specimens. Here we present a novel wavefront detector, based on pupil sampling
with sub-apertures, which measures the aberrated wavefront phase at each
position of the specimen. Based on this measurement, we propose a region-wise
deconvolution that provides an anisoplanatic reconstruction of the sample
image. Our results indicate that the measurement and correction of the
aberrations can be performed in a wide-field fluorescence microscope over its
entire field of view.Comment: 5 pages, 4 figure
Phase-Retrieved Tomography enables imaging of a Tumor Spheroid in Mesoscopy Regime
Optical tomographic imaging of biological specimen bases its reliability on
the combination of both accurate experimental measures and advanced
computational techniques. In general, due to high scattering and absorption in
most of the tissues, multi view geometries are required to reduce diffuse halo
and blurring in the reconstructions. Scanning processes are used to acquire the
data but they inevitably introduces perturbation, negating the assumption of
aligned measures. Here we propose an innovative, registration free, imaging
protocol implemented to image a human tumor spheroid at mesoscopic regime. The
technique relies on the calculation of autocorrelation sinogram and object
autocorrelation, finalizing the tomographic reconstruction via a three
dimensional Gerchberg Saxton algorithm that retrieves the missing phase
information. Our method is conceptually simple and focuses on single image
acquisition, regardless of the specimen position in the camera plane. We
demonstrate increased deep resolution abilities, not achievable with the
current approaches, rendering the data alignment process obsolete.Comment: 21 pages, 5 figure