Bessel beam

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

Design and imaging properties of a laser scanning microscope with a position-sensitive detector

Abstract: An economical method of microscopic image formation that employs a raster-scanning laser beam focused on a sample, while a non-imaging detector receives the scattered light, is presented. The images produced by this method are analogous to the scanning electron microscopy with visible effects of shadowing and reflection. Compared to a conventional wide-field imaging system, the system allows for a greater flexibility, as the variety of optical detectors, such as PMT and position-sensitive quadrant photodiode can be used to acquire images. The system demonstrates a simple, low-cost method of achieving the resolution on the order of a micron. A further gain in terms of resolution and the depth of focus by using Bessel rather than Gaussian beams is discussed.

Mode conversion via wavefront shaping.

Abstract: In recent years, wavefront shaping has been utilized to control and correct distorted light for enhancing a bright spot, generation of a Bessel beam or darkening a complete area at the output of a scattering system. All these outcomes can be thought of as enhancing a particular mode of the output field. In this letter, we study the relation between the attainable enhancement factor, corresponding to the efficiency of mode conversion, and the field distribution of the target mode. Working in the limit of a thin diffuser enables not only a comparison between experimental and simulated results, but also allows for derivation of an analytic formula. These results shed light on the ability to use a scattering medium as a mode converter and on the relationship between the desired shape and the efficiency.

1 Bit Non-Diffractive Vortex Beam Generator Based on FSS in Microwave Region

Abstract: In this article, a low-profile planar 1 bit non-diffractive vortex beam generator is proposed based on frequency selective surface (FSS) in microwave region. The characteristic of Bessel beam is introduced to control the divergence of the vortex beam. The proposed unit cell is analyzed through equivalent circuit model. The main resonance is provided by the coupling between the patches and the circular slot grid. A cross patch is embedded in the slot to form another resonance. Two elements with 0° and 180° transmission phase are designed to discretize the phase distribution of the metalens. The simulation results show that the metalens can generate fulfill non-diffracting transmission upon a distance of the $32\lambda _{\mathbf {0}}$ , verifying the effectiveness of the proposed method.

Non-diffracting beams from surface-emitting lasers

Abstract: We present an overview of recent advances in generation of non-diffracting (Bessel) beams from surface-emitting lasers, such as electrically and optically pumped VECSELs, and discuss their applications in optical trapping/tweezing and manipulation of micromachines. Our experiments on VECSEL-generated watt power level Bessel beams with central lobe diameters of a few to tens micrometers suggest that the semiconductor surface-emitting lasers are the best candidates for replacement of gas and solid-state counterparts for power-demanding applications in optical manipulation.