简介:Thehigh-powerlaserbeaminthefinalopticsassemblyofhigh-powerlaserfacilitiesisoftenmodulatedbycontaminationparticles,whichmaycauselocalhighlightintensity,therebyincreasingthefilamentarydamageprobabilityforopticalcomponents.Tostudythegeneraldesignbasisforafinalopticsassemblytodecreasetheriskoffilamentarydamage,different-sizedcontaminationparticlesdepositedonacomponentsurfacearesimulatedtomodulatea351-nmlaserbeambasedontheopticaltransmissiontheory,andthecorrespondingsimulationresultsareanalyzedstatisticallyintermsofthepropagationcharacteristicandthelightfieldintensitydistributionofthemodulatedlaserbeam.Thestatisticalresultsshowthatcomponentthicknessanddistancebetweencomponentscantosomeextentbeoptimizedtoreducetheappearanceoflocalhighlightintensity,andthegeneraldesignbasisofcomponentthicknessandarrangementaregivenfordifferentcontrollevelsofparticlesizes.Moreover,thestatisticalresultscanalsopredictthelaserbeamqualityapproximatelyundertheexistingopticsdesignandenvironmentalcleanliness.Theoptimizeddesignforfinalopticsassemblybasedonenvironmentalcleanlinesslevelisusefultoprolongthelifetimeofopticsandenhancetheoutputpowerofhigh-powerlaserfacilities.
简介:Ashocktubeisusedtoinvestigatethebubbledynamicsundersuddendecreaseofambientpressure.Boththeoscillatingandmonotonouslygrowingbubblesweresimultaneouslyobserved.TheoreticalapproachisbasedontheRayleigh-PlessetandHerring'sequationsforincompressibleandcompressibleliquids,respectively.Consideringthelinearapproximationoftheseequationsforthequasiequilibriumstate,twocriticalWebernumbersaredefined.Theyenableonetopredictthefollowingmodesofthebubbleexpansion:(i)unboundedgrowth,(ii)asymptoticgrowthtolimitedvolumeand(iii)attenuatedoscillations,dependingonthepressureforce,viscosityandcompressibilityoftheliquid.