Bessel beam

About: Bessel beam is a research topic. Over the lifetime, 1946 publications have been published within this topic receiving 42264 citations.

Deep skin structural and microcirculation imaging with extended-focus OCT

Abstract: We present an extended focus OCT system for dermatologic applications that maintains high lateral resolution over a large depth range by using Bessel beam illumination. More, Bessel beams exhibit a self-reconstruction property that is particularly useful to avoid shadowing from surface structures such as hairs. High lateral resolution and high-speed measurement, thanks to a rapidly tuning swept source, allows not only for imaging of small skin structures in depth but also for comprehensive visualization of the small capillary network within the human skin in-vivo. We use this information for studying temporal vaso-responses to hypothermia. In contrast to other perfusion imaging methods such as laser Doppler imaging (LDI), OCT gives specific access to vascular responses in different vascular beds in depth.

Microwave Bessel-Beam Propagation through Spatially Inhomogeneous Media

Abstract: Long range wireless power transmission (WPT) is a critical technology for the development of remote power systems for air and space vehicles as well as for point-to-point transmission on Earth. This can be achieved using either a laser for transmission in the infrared to optical frequency domain or by using microwaves. The objective of this research is to study the application of microwave power transmission (MPT) through the use of a so-called Bessel-beam whose unique propagation properties include a selfhealing ability as well as non-diffractive properties. These two unique properties lead to an increase in the efficiency of microwave power transmission. In this research the propagation of a microwave Bessel-beam through a spatially inhomogeneous medium will be simulated in MATLAB using a plane wave spectrum representation of the electromagnetic beam field. The spatially inhomogeneous medium of interest here is the Earth’s atmosphere whose electromagnetic properties (dielectric permittivity and electric conductivity) vary with altitude up through the ionosphere. The purpose of this research is to determine how efficiently a microwave Bessel beam can propagate in point-to-point transmission through the Earth’s atmosphere as well as between satellites in Earth orbit. Dedication To my parents who have supported me every step of the way, to my friends for their continuous motivation, and to Kenzie for all her love and patience.

Laser direct write near-field nanopatterning using optically trapped microspheres

Abstract: We use Bessel beam optical traps to self-position microsphere objectives near surfaces. Pulsed laser illumination of these objectives is used to perform near-field direct-write subwavelength optical nanopatterning with 100 nm feature sizes.

Bessel beam writing multi-core fiber grating device

Abstract: The invention relates to a fiber grating manufacturing technology and provides a new long-period fiber grating writing device. To this end, a Bessel beam writing multi-core fiber grating device is composed of a laser, an axicon and a displacement stage. The light emitted by the laser passes through the cylindrical axicon to form an elongated spot. The elongated spot passes through a multi-core orsingle-core fiber to be exposed. Then, the displacement stage moves the fiber at a specific period in order to expose the next point. The above processes are repeated until the entire fiber grating iswritten. The Bessel beam writing multi-core fiber grating device is mainly used for the production of fiber gratings.