Non-Invasive Imaging Through Scattering Medium by Using a Reverse Response Wavefront Shaping Technique

Abstract

Fundamental challenge of imaging through a scattering media has been resolved by various approaches in the past two decades. Optical wavefront shaping technique is one such method in which one shapes the wavefront of light entering a scattering media using a wavefront shaper such that it cancels the scattering effect. It has been the most effective technique in focusing light inside a scattering media. Unfortunately, most of these techniques require direct access to the scattering medium or need to know the scattering properties of the medium beforehand. Through the novel scheme presented on this paper, both the illumination module and the detection are on the same side of the inspected object and the imaging process is a real time fast converging operation. We model the scattering medium being a biological tissue as a matrix having mathematical properties matched to the physical and biological aspects of the sample. In our adaptive optics scheme, we aim to estimate the scattering function and thus to encode the intensity of the illuminating laser light source using DMD (Digital Micromirror Device) with an inverse scattering function of the scattering medium, such that after passing its scattering function a focused beam is obtained. We optimize the pattern to be displayed on the DMD using Particle Swarm Algorithm (PSO) which eventually help in retrieving a 1D object hidden behind the media.

Optical reciprocity induced wavefront shaping for axial and lateral shifting of focus through a scattering medium

“…1 a). We, in our previous work 38 , laid the theoretical foundation to a novel technique of focusing light through a scattering medium non-invasively, i.e., the illumination and detection are on the same side of the media (Fig. 1 b).…”

Towards smart optical focusing: deep learning-empowered dynamic wavefront shaping through nonstationary scattering media

“…5(a)-5(c), under circumstances without sudden disturbance, the PBR target can always be reached after fine-tuning using the adaptive recursive algorithm (gray line), while the traditional algorithm (red line) never reaches the target. In these circumstances, the adaptive recursive algorithm always shows much better GFP (17)(18)(19)(20)(21)(22)(23)(24)(25) than traditional algorithm results (8)(9)(10)(11)(12)(13)(14)(15)(16)(17). As seen from Fig.…”

“…Although the occurrence of perturbations leads to inevitable increase in the GTE, as observed in both Figs. 4(b) and 2(l), the adaptive recursive algorithm still demonstrates much lower GTE in experiments (2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15) than that achieved by the traditional algorithm (13)(14)(15)(16)(17)(18)(19)(20)(21)(22)(23)(24)(25). The reduction percentage in the GTE realized by the adaptive recursive method over the traditional one is 38%-93%.…”

“…Although visually random, the way that light is scattered is actually deterministic within a certain time window (usually referred to as speckle correlation time) [2]. Built upon this property, various approaches have been inspired, such as time reversal [3][4][5][6], pre-compensated wavefront shaping [2,[7][8][9][10][11][12][13], and memory effect [1,[14][15][16], to obtain optical focusing and imaging through scattering media. Time reversal methods, such as time-reversed ultrasonically encoded (TRUE) method [17] and time reversal of variance encoded light (TROVE) [18], take advantage of guide stars (e.g., focused ultrasonic modulation) to encode diffused light; then, only the encoded light is time-reversed and focused inside the scattering medium.…”

Improving Compressed Sensing Image Reconstruction Based on Atmospheric Modulation Using the Distributed Cumulative Synthesis Method

“…Further, these seemingly random scattered photons also carry some target information. Wavefront shaping [2,[7][8][9] is a method that uses scattering media to achieve focusing and imaging at a desired position. This method requires auxiliary equipment in most cases, which limits its application in practice.…”