OAM light propagation through tissue

Abstract

A major challenge in use of the optical spectrum for communication and imaging applications is the scattering of light as it passes through diffuse media. Recent studies indicate that light beams with orbital angular momentum (OAM) can penetrate deeper through diffuse media than simple Gaussian beams. To the best knowledge of the authors, in this paper we describe for the first time an experiment examining transmission of OAM beams through biological tissue with thickness of up to a few centimeters, and for OAM modes reaching up to 20. Our results indicate that OAM beams do indeed show a higher transmittance relative to Gaussian beams, and that the greater the OAM, the higher the transmittance also up to 20, Our results extend measured results to highly multi scattering media and indicate that at 2.6 cm tissue thickness for OAM of order 20, we measure nearly 30% more power in comparison to a Gaussian beam. In addition, we develop a mathematical model describing the improved permeability. This work shows that OAM beams can be a valuable contribution to optical wireless communication (OWC) for medical implants, optical biological imaging, as well as recent innovative applications of medical diagnosis.

Imaging through diffuse media using multi-mode vortex beams and deep learning

“…The former two objectives can be achieved using structured light sources, and the latter can be addressed by implementing deep learning algorithms with sufficient training. Studies have shown that imparting a topological charge to beams used for optical imaging enhances optical imaging systems 19 – 22 and improves the beams' penetration depth 5 , 23 – 25 . It has also been demonstrated that vortex beams have more transmissivity through scattering media than Gaussian beams 22 , 23 , 25 , 26 .…”

“…Studies have shown that imparting a topological charge to beams used for optical imaging enhances optical imaging systems 19 – 22 and improves the beams' penetration depth 5 , 23 – 25 . It has also been demonstrated that vortex beams have more transmissivity through scattering media than Gaussian beams 22 , 23 , 25 , 26 .…”

“…The use of vortex beams, coupled with a deep learning algorithm, allows us to gain significant insight into the potential impact of vortex beams to enhance the image reconstruction quality and their potential applications in imaging through diffuse media. These applications include biomedical imaging, imaging through a fog, non-destructive testing, computer-assisted surgery, and autonomous vehicular systems 23 , 26 , 34 . In this article, we investigate imaging through diffuse media by means of numerical simulations and experiments.…”

Conservation of orbital angular momentum and polarization through biological waveguides

“…Beams with orbital angular momentum (OAM or vortex beam) have been used previously in classical and quantum communication 29 – 32 and more recently in biomedical applications for noninvasive imaging and diagnosis of tissues 33 . Recent studies indicate possible benefits of using light beams with orbital angular momentum for deep penetration and higher transmittance propagation through dispersive and scattering media 34 , 35 . This inspired our investigation into the transmission of vortex beam and polarization through biological waveguides.…”

Revealing the invariance of vectorial structured light in perturbing media

“…Given the importance of these structured light fields, much attention has focused on their propagation through optical systems that are paraxial [35], guided [36] and tight focussing [37,38], as well as in perturbing media such as turbid [39][40][41][42], turbulent [43][44][45][46][47][48][49][50] and underwater [51][52][53]. The conclusions are seemingly contradictory, with compelling evidence that the vectorial structure is stable, and equally compelling evidence that it is not, while the specific nature of each study prohibits making general conclusions on the robustness of vectorial light in arbitrary complex media.…”