Conservation of orbital angular momentum and polarization through biological waveguides

Abstract

A major roadblock to the development of photonic sensors is the scattering associated with many biological systems. We show the conservation of photonic states through optically self-arranged biological waveguides, for the first time, which can be implemented to transmit light through scattering media. The conservation of optical properties of light through biological waveguides allows for the transmission of high bandwidth information with low loss through scattering media. Here, we experimentally demonstrate the conservation of polarization state and orbital angular momentum of light through a self-arranged biological waveguide, several centimeters long, in a sheep red blood cell suspension. We utilize nonlinear optical effects to self-trap cells, which form waveguides at 532 nm and 780 nm wavelengths. Moreover, we use the formed waveguide channels to couple and guide probe beams without altering the information. The formed biological waveguides are in a sub-diffusive scattering regime, so the photons’ information degrades insignificantly over several centimeters of propagation through the scattering media. Our results show the potential of biological waveguides as a methodology for the development of novel photonic biosensors, biomedical devices that require optical wireless communication, and the development of new approaches to noninvasive biomedical imaging.

Light guiding through suspensions of red blood cells

“…At similar laser power and sample preparation conditions to the previous Gaussian beam experiments, an optical vortex beam with orbital angular momentum can also form stable waveguides at different wavelengths. The vortex beam preserves its donut shape and orbital angular momentum in RBC suspensions over several centimeters distance (Figure 2) [14]. In addition, both Gaussian and vortex beams are capable of nonlinear coupling into waveguide channels and both preserve their orbital angular momentum and intensity distribution [14].…”

“…The vortex beam preserves its donut shape and orbital angular momentum in RBC suspensions over several centimeters distance (Figure 2) [14]. In addition, both Gaussian and vortex beams are capable of nonlinear coupling into waveguide channels and both preserve their orbital angular momentum and intensity distribution [14].…”

“…To modulate phase or polarization of the beams, the vortex phase plates or a combination of half-wave plates and quarter-wave plates are introduced into the beam paths. The experimental setup diagrams, the exact details of the experiments and sample preparation procedures have been published in previous works [13,14]. At low laser power, the focused laser beam diffracts and scatters through the RBC suspension.…”

“…Figure 1 illustrates guiding of a low power probe beam at different wavelengths by the green pump beam through RBC suspension [13]. Furthermore, even though beams propagate through scattering RBC suspensions, the output pump beam and the probe beam preserver their polarization states (circular and linear polarization states) [14].…”

Harnessing spin and orbital angular momentum light for optimal algae growth

“…Previous studies have shown that under certain conditions, the transmittance of LG beams in certain biological tissues and scattering media is higher than that of ordinary lasers [16][17][18] . Due to the scattering and biological tissue characteristics of Chlorella fluid, we also tested its transmittance using several different types of light sources.…”