Understanding Laser Beam Brightness a Review and New Prospective in Material Processing
Total Page:16
File Type:pdf, Size:1020Kb
Load more
Recommended publications
-
Measurement of M 2-Curve for Asymmetric Beams by Self
sensors Article Measurement of M2-Curve for Asymmetric Beams by Self-Referencing Interferometer Wavefront Sensor Yongzhao Du 1,2 1 College of Engineering, Huaqiao University, Quanzhou 362021, China; [email protected]; Tel.: +86-188-1599-2396 2 Fujian Provincial Academic Engineering Research Centre in Industrial Intelligent Techniques and Systems, Huaqiao University, Quanzhou 362021, China Academic Editor: Vittorio M. N. Passaro Received: 17 October 2016; Accepted: 23 November 2016; Published: 29 November 2016 2 2 Abstract: For asymmetric laser beams, the values of beam quality factor Mx and My are inconsistent if one selects a different coordinate system or measures beam quality with different experimental conditionals, even when analyzing the same beam. To overcome this non-uniqueness, a new beam quality characterization method named as M2-curve is developed. The M2-curve not only contains the beam 2 2 quality factor Mx and My in the x-direction and y-direction, respectively; but also introduces a curve 2 of Mxa versus rotation angle a of coordinate axis. Moreover, we also present a real-time measurement method to demonstrate beam propagation factor M2-curve with a modified self-referencing Mach-Zehnder interferometer based-wavefront sensor (henceforth SRI-WFS). The feasibility of the proposed method is demonstrated with the theoretical analysis and experiment in multimode beams. The experimental results showed that the proposed measurement method is simple, fast, and a single-shot measurement procedure without movable parts. Keywords: laser beam characterization; beam quality M2-curve; self-referencing interferometer wavefront sensor; fringe pattern analysis 1. Introduction Laser beam characterization plays an important role for laser theoretical analysis, designs, and manufacturing, as well as medical treatment, laser welding, and laser cutting and other applications. -
Understanding Laser Beam Brightness: a Review and New Prospective in Material Processing
Understanding Laser Beam Brightness: A review and new prospective in material processing Shukla, P, Lawrence, J & Zhang, Y Author post-print (accepted) deposited by Coventry University’s Repository Original citation & hyperlink: Shukla, P, Lawrence, J & Zhang, Y 2015, 'Understanding Laser Beam Brightness: A review and new prospective in material processing' Optics and Laser Technology, vol 75, pp. 40-51 https://dx.doi.org/10.1016/j.optlastec.2015.06.003 DOI 10.1016/j.optlastec.2015.06.003 ISSN 0030-3992 ESSN 1879-2545 Publisher: Elsevier NOTICE: this is the author’s version of a work that was accepted for publication in Optics and Laser Technology. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Optics and Laser Technology, [75, (2017)] DOI: 10.1016/j.optlastec.2015.06.003 © 2017, Elsevier. Licensed under the Creative Commons Attribution-NonCommercial- NoDerivatives 4.0 International http://creativecommons.org/licenses/by-nc-nd/4.0/ Copyright © and Moral Rights are retained by the author(s) and/ or other copyright owners. A copy can be downloaded for personal non-commercial research or study, without prior permission or charge. This item cannot be reproduced or quoted extensively from without first obtaining permission in writing from the copyright holder(s). The content must not be changed in any way or sold commercially in any format or medium without the formal permission of the copyright holders. -
Understanding Laser Beam Parameters Leads to Better System Performance and Can Save Money
Understanding Laser Beam Parameters Leads to Better System Performance and Can Save Money Lasers became the first choice of energy source for a steadily increasing number of applications in science, medicine and industry because they deliver light energy in an exceedingly useful form and set of features. A comprehensive analysis of lasers and laser systems goes far beyond the measurement of just output power and pulse energy. The most commonly measured laser beam parameters besides power or energy are beam diameter (or radius), spatial intensity distribution (or profile), divergence and the beam quality factor (or beam parameter product). In many applications, these parameters define success or failure and, therefore, their control and optimization seems to be crucial. Beam Diameter (Radius, Width) The beam diameter (generally defined as twice the beam radius, no matter what the particular definition of the beam radius is) is the most important propagation-related attribute of a laser beam. In case of a perfect top-hat (or flat-top) profile the beam diameter is clear but most laser beams have other transverse shapes or profiles (for example, Gaussian) in which case the definition and measurement of the beam diameter is not trivial. The boundary of arbitrary optical beams is not clearly defined and, in theory at least, extends to infinity. Consequently, the dimensions of laser beams cannot be defined and measured as easily as the dimensions of hard physical objects. A good example would be the task of measuring the width of soft cotton balls using vernier callipers. A commonly used definition of the beam diameter is the width at which the beam intensity has fallen to 1/e² (13.5%) of its peak value. -
Gaussian Beam - Wikipedia, the Free Encyclopedia Gaussian Beam from Wikipedia, the Free Encyclopedia
8/16/13 Gaussian beam - Wikipedia, the free encyclopedia Gaussian beam From Wikipedia, the free encyclopedia In optics, a Gaussian beam is a beam of electromagnetic radiation whose transverse electric field and intensity (irradiance) distributions are well approximated by Gaussian functions. Many lasers emit beams that approximate a Gaussian profile, in which case the laser is said to be operating on the fundamental transverse mode, or "TEM00 mode" of the laser's optical resonator. When refracted by a diffraction-limited lens, a Gaussian beam is transformed into another Gaussian beam (characterized by a different set of parameters), which explains why it is a convenient, widespread model in laser optics. The mathematical function that describes the Gaussian beam is a solution to the paraxial form of the Helmholtz equation. The solution, in the form of a Gaussian function, represents the complex amplitude of the beam's electric field. The electric field and Instantaneous intensity of a Gaussian magnetic field together propagate as an electromagnetic wave. A description of just one of the two fields is sufficient to beam. describe the properties of the beam. The behavior of the field of a Gaussian beam as it propagates is described by a few parameters such as the spot size, the radius of curvature, and the Gouy phase.[1] Other solutions to the paraxial form of the Helmholtz equation exist. Solving the equation in Cartesian coordinates leads to a family of solutions known as the Hermite–Gaussian modes, while solving the equation in cylindrical coordinates leads to the Laguerre–Gaussian modes.[2] For both families, the lowest-order solution describes a Gaussian beam, while higher-order solutions describe higher-order transverse modes in an optical resonator. -
Laser Beam Analysis Using Image Processing
ministry of higher education & scientific research University of Technology Laser & Optoelectronics Engineering Department Laser Beam Analysis Using Image Processing A Project Submitted to the Laser and optoelectronics Engineering Department / University of Technology in Partial Fulfillment of The Requirements for the Degree of B.Sc in Laser and Optoelectronics Engineering/Laser Engineering By Mayss Khudhur Abbass Supervised by Dr.Husham Muhamed Ahmed ﺟﻤﺎدي اﻟﺜﺎﻧﯿﺔ ١٤٣١ may 2010 IV Abstract The laser beam profiles captured by CCD camera processed and analyzed by using 2Dgraphic and displayed on the monitor. The analysis of the He-Ne profiles and laser diode profiles are presented. The results showed that the He-Ne laser emits a pure Gaussian beam, whereas the diode laser emits an elliptical beam shape. The laser beam profile analysis developed to study the intensity distribution, the laser power, number of modes and the laser beam, these parameters are quite important in many applications such as the medical, industrial, military, Laser cutting, Nonlinear optics, Alignment, Laser monitoring, Laser and laser amplifier development, Far-field measurement, Education. The analysis of the image profile can be used in determination the distance of the objects depending on the distribution of the spot contours of the laser beam with its width. As well as it can be used to capturing images to the objects and determining their distance and the shape of the objects. V contents Chapter one 1.1 Introduction Chapter two ( Laser beam profile-principles and definition ) 2.1 Transverse electromagnetic modes …………...….…………….……….3 2.2 Beam diameter and spot propagation ……..……..…………..…….…...4 2.3 Gaussian beam propagation …………………………...……..…..…..….5 2.3.1 Beam waist and divergence.