SAND2000-0710 CLaser Beam Shaping TechniquesFred M.Dickey,*Louis S.Weichman,Richard N.ShagamAPR442000RECEIVEDSandia National Laboratories,MS 0328,Albuquerque,NM 87185-0328ABSTRACTIndustrial,military,medical,and research and development applications of lasers frequently require a beam with a specifiedirradiance distribution in some plane.A common requirement is a laser profile that is uniform over some cross-section.Such applications include laser/material processing,laser material interaction studies,fiber injection systems,opticaldata/image processing,lithography,medical applications,and military applications.Laser beam shaping techniques can bedivided in to three areas:apertured beams,field mappers,and multi-aperture beam integrators.An uncertainty relationexists for laser beam shaping that puts constraints on system design.In this paper we review the basics of laser beamshaping and present applications and limitations of various techniques.Keywords:Laser beam shaping,beam profiles,field mapping,beam integrators1.INTRODUCTIONBeam shaping is the process of redistributing the irradiance and phase of a beam of optical radiation.The beam shape isdefined by the irradiance distribution and the phase of the shaped beam is a major factor in determining the propagationproperties of the beam profile.Applications of beam shaping include laser/material processing,laser/material interactionstudies,laser weapons,optical data/image processing,lithography,printing,and laser art patterns.In this paper we providean overview of the techniques for producing shaped beams that are uniform over a specified cross-section.The shapedbeam cross section may be arbitrary,including rectangular,circular,triangular,hexagonal,and ring shaped.In-depthinfromation is provided by the references.The theory and techniques of laser beam shaping are addressed in the bookedited by Dickey and Holswade.Laser beam shaping techniques can be divided into three broad classes.The first is the trivial,but useful,aperturing of thebeam illustrated in Fig.1.In this case the beam is expanded and an aperture is used to select a suitably flat portion of thebeam.The resulting irradiance can be imaged with magnification to control the size of the output beam.The majorFig.1 Uniform irradiance obtained by aperturing input beamCorrespondence:Email:fmdicke@sandia.gov;Telephone:505 8449660;Fax:505 8449554DISCLAIMERThis report was prepared as an account of work sponsoredby an agency of the United States Government.Neitherthe United States Government nor any agency thereof,norany of their employees,make any warranty,express orimplied,or assumes any legal liability or responsibility forthe accuracy,completeness,or usefulness of anyinformation,apparatus,product,or process disclosed,orrepresents that its use would not infringe privately ownedrights.Reference herein to any specific commercialproduct,process,or service by trade name,trademark,manufacturer,or otherwise does not necessarily constituteor imply its endorsement,recommendation,or favoring bythe United States Government or any agency thereof.Theviews and opinions of authors expressed herein do notnecessarily state or reflect those of the United StatesGovernment or any agency thereof.DISCLAIMERPortions of this document may be illegiblein electronic image products.Images areproduced from the best available originaldocument.