Exploiting scattering media for exploring 3D objects

Abstract

Scattering media, such as diffused glass and biological tissue, are usually treated as obstacles in imaging. To cope with the random phase introduced by a turbid medium, most existing imaging techniques recourse to either phase compensation by optical means or phase recovery using iterative algorithms, and their applications are often limited to two-dimensional imaging. In contrast, we utilize the scattering medium as an unconventional imaging lens and exploit its lens-like properties for lensless three-dimensional (3D) imaging with diffraction-limited resolution. Our spatially incoherent lensless imaging technique is simple and capable of variable focusing with adjustable depths of focus that enables depth sensing of 3D objects that are concealed by the diffusing medium. Wide-field imaging with diffraction-limited resolution is verified experimentally by a single-shot recording of the 1951 USAF resolution test chart, and 3D imaging and depth sensing are demonstrated by shifting focus over axially separated objects.

Single‐shot speckle correlation fluorescence microscopy in thick scattering tissue with image reconstruction priors

“…Here, we only imaged 2D objects, but there has been recent progress in depth‐resolved SCI . 3D imaging in deep tissue or even the ability to select for a single plane would greatly expand the practicality of this technique.…”

“…Furthermore, scattering decorrelation over time can benefit this technique by allowing for averaging over multiple independent speckle patterns. Numerous follow‐up SCI studies are motivated by the potential of fluorescence imaging within thick tissue but, to our knowledge, have only been demonstrated with scattered laser illumination and in geometries where the scatterer is in the far field relative to the target object . Spurred by new insights into speckle correlations , we set out to adapt SCI to fluorescence microscopy within scattering tissue.…”

A compact single channel interferometer to study vortex beam propagation through scattering layers

“…In the first type, optical signal processing [6][7][8], correlation techniques [9][10][11][12][13] and phase retrieval algorithms [14,15] have been developed to decode a speckle signature and convert it into useful information. A second direction of research is to develop adaptive aberration correction methods to compensate for the disturbance introduced by the scattering medium [16,17].…”

Complex field measurement in a single pixel hybrid correlation holography

“…The phase imaging is essential to examine the complex-valued object. However, when the object is obscured by the scattering medium or illuminated by a random light [8][9][10][11][12][13][14][15], recovery of the non-stochastic object through phase imaging is a challenging task. Such issues have been a matter of investigation since long, and several techniques such as adaptive optics [9], correlation optics [10], and phase conjugation [15] have been proposed.…”