Integration of high-resolution imaging through scattering medium into a disposable micro-endoscope via projection of 2D spots-array

Sci Rep. 2023 Nov 13;13(1):19774. doi: 10.1038/s41598-023-46657-0.

Abstract

The objective of this research includes integration of high-resolution imaging through scattering medium, such as blood, into a disposable micro-endoscope. A fiber laser integrated into the micro-endoscope as part of its illumination channel, allows to project a tunable array of spots of light onto an object, that is located behind the scattering medium. We have a laser fiber as part of the illumination channel of a disposable micro-endoscope. By using proper optics, we convert the temporal modulation of the laser into spatial distribution. Thus, the result is generation of spatial spots when using a pulsed laser. The detection channel is a holographic recording of the collected back scattered light, that allows extraction of the electrical field. By time integrating the field we obtain the realization of the spatial array of illumination spots formed on top of the inspected object and behind the scattering medium. By changing the temporal modulation of the illumination laser (changing its temporal photonic signals), we can tune the positions of the spots in the illumination array. If the distance between the projected spots is larger than the imaging resolution, then by applying localization microscopy algorithms together with scanning of the position of the spots in the array, will yield a high-resolution reconstruction of the inspected object. We theoretically and experimentally demonstrate the discussed operation principle and show the potential of the proposed concept as a modality in medical endoscopic procedures.