Laser beam shape and curvature radius of the laser wavefront passing through ZnO nanostructures

Orientating manipulations of cylindrical particles were performed by optical tweezers. Vertical and horizontal manipulations of Escherichia coli (E. coli) were carried out by changing the trapping depth and the focused laser beam shape. It was found that carbon nanotubes bundles (CNTBs) could be rotated in the linear polarized optical trap until it orientated its long axis along the linear polarization direction of the laser beam. However, E.coli could not be orientated in this way. Corresponding mechanisms were discussed based on the anisomeric electric characters of CNTBs. These orientation technologies of cylindrical objects with optical trap have potential applications in assembling nano-electric devices.

Download Full-text

Effect of laser beam shape parameters on photothermal deflection densitometers

Analytical Chemistry ◽

10.1021/ac00273a031 ◽

1984 ◽

Vol 56 (9) ◽

pp. 1674-1677 ◽

Cited By ~ 16

Author(s):

Tsuey Ing. Chen ◽

Michael D. Morris

Keyword(s):

Laser Beam ◽

Shape Parameters ◽

Beam Shape ◽

Photothermal Deflection

Download Full-text

Dynamic control of laser beam shape for heat treatment

Journal of Laser Applications ◽

10.2351/1.5040647 ◽

2018 ◽

Vol 30 (3) ◽

pp. 032507 ◽

Cited By ~ 6

Author(s):

Paula Sancho ◽

M. Angeles Montealegre ◽

Jesús Dominguez ◽

Piera Alvarez ◽

Juan Isaza

Keyword(s):

Heat Treatment ◽

Laser Beam ◽

Dynamic Control ◽

Beam Shape

Download Full-text

Research on method for laser beam shape parameters detection

10.1117/12.2068680 ◽

2014 ◽

Author(s):

Jun-hong Su ◽

Zhao-feng Bai

Keyword(s):

Laser Beam ◽

Shape Parameters ◽

Beam Shape

Download Full-text

Influence of Excimer Laser Beam Shape on Poly-Si Crystallisation

Japanese Journal of Applied Physics ◽

10.1143/jjap.43.5114 ◽

2004 ◽

Vol 43 (8A) ◽

pp. 5114-5121 ◽

Cited By ~ 10

Author(s):

S. D. Brotherton ◽

D. J. McCulloch ◽

J. P. Gowers

Keyword(s):

Laser Beam ◽

Excimer Laser ◽

Beam Shape

Download Full-text

Linear-core-array optical fiber based laser beam shape convertor

10.1117/12.884726 ◽

2011 ◽

Author(s):

Libo Yuan ◽

Xiaoliang Zhu ◽

Ai Zhou ◽

Qiang Dai ◽

Fengjun Tian

Keyword(s):

Laser Beam ◽

Optical Fiber ◽

Beam Shape

Download Full-text

Beam Patterns of the Five-hundred-metre Aperture Spherical Telescope: Optimisation

Publications of the Astronomical Society of Australia ◽

10.1017/pasa.2013.19 ◽

2013 ◽

Vol 30 ◽

Cited By ~ 1

Author(s):

B. Dong ◽

J. L. Han

Keyword(s):

Curvature Radius ◽

Radio Waves ◽

Optimal Parameters ◽

Similar Extent ◽

Focal Distance ◽

Beam Shape ◽

Small Shift ◽

Aperture Efficiency ◽

The Stability ◽

Beam Patterns

AbstractThe Five-hundred-metre Aperture Spherical Telescope (FAST) uses adaptive spherical panels to achieve a huge collecting area for radio waves. In this paper, we try to explore the optimal parameters for the curvature radius of spherical panels and the focal distance by comparison of the calculated beam patterns. We show that to get the best beam shape and maximum gain, the optimal curvature radius of panels is around 300 m, and a small shift in the focal distance of a few cm is needed. The aperture efficiency can be improved by ~10% at 3 GHz by this small shift. We also try to optimise the panel positioning for the best beam, and find that panel shifts of a few mm can improve the beam pattern by a similar extent. Our results indicate that accurate control of the feed and panel positions to the mm level is very crucial for the stability of FAST's observational performance.

Download Full-text

The effect of object shape and laser beam shape on lidar system resolution

10.1117/12.2225197 ◽

2016 ◽

Author(s):

Hongchang Cheng ◽

Jingyi Wang ◽

Jun Ke

Keyword(s):

Laser Beam ◽

Lidar System ◽

Beam Shape ◽

Object Shape

Download Full-text

Study on Macroscopic Morphology and Microstructure of Single Ni60 Laser Clad Tracks Prepared Using a Variable Laser Beam Shaper

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.887-888.1091 ◽

2014 ◽

Vol 887-888 ◽

pp. 1091-1095

Author(s):

You Zheng Sun ◽

Si Yu Wang ◽

Daniel Wellburn ◽

Shuo Shang ◽

Jian Cheng ◽

...

Keyword(s):

Temperature Distribution ◽

Laser Beam ◽

Cross Section ◽

Steel Industry ◽

Alloy Powder ◽

Low Energy ◽

Beam Shape ◽

Cross Section Area ◽

Section Area ◽

Density Ratios

The objective of the present study was to find the influence of laser beam shape on macroscopic morphology and microstructure of single Ni60 laser clad tracks. Laser cladding of Ni60 alloy powder can be used to manufacture and remanufacture backup rollers for the steel industry. Controlling temperature distribution can assist with achieving favorable macroscopic morphology and microstructure. Five different beam profiles were used in our experiment to prepare clad tracks. The beam profiles varied in terms of the ratio of energy densities between the internal and external parts. The macroscopic morphology and microstructure was tested using SEM. The study founds decreasing the ratio is possible to achieve wider clad tracks with a larger cross section area. It was found that microstructure in upper region tended to form net-like dendrite microstructure at low energy density ratios.

Download Full-text