激光专业英语1讲解

LaserEnglishLOGOPage2教学参考书1、《激光和电光学》(英文版)C.C.Davis主编世界图书出版公司2、《电子科学与技术专业英语.光电子技术分册》张爱红主编哈尔滨工业大学出版社Page31、NewWordsandphrases1、Wavelength波长2、Power功率3、BeamQuality光束质量4、BeamDiameter光斑直径5、Divergence发散角6、PowerStability功率稳定性7、Powersupply电源输入8、coolingsystem冷却方式9、nearTEM00近基模10、Outputpower输出功率11、Repetitionfrequency脉冲重复频率Page412、Pulsewidth脉宽13、Spacemode空间模式14、Diode-pumped二极管泵浦15、Specification规格、说明书Page5气体激光GASLASERS1氦氖激光He-NeLasers2金属蒸气激光MetalVaporLasers3氩离子激光ArgonLasers4氪离子激光KryptonLasers5二氧化碳激光(气流型)CO2(GasFlowtype)Lasers6二氧化碳激光(脉冲,TEA型)CO2(Pulsed,TEA)Lasers7二氧化碳激光(密封型)CO2(Sealedtube)Lasers8二氧化碳激光(波导型)CO2(Waveguide)Lasers9一氧化碳激光COLasers10氦镉激光He-CdLasers11氮分子激光NitrogenLasersPage612准分子激光ExcimerLasers13氙分子激光XenonLasers14固体激光SOLIDSTATELASERS15红宝石激光RubyLasers16半导体激光(0.60μm带)Semiconductor(0.60μm)Lasers17Nd:YAG激光(脉冲式)Nd:YAG(Pulsed)Lasers18Nd:YAG激光(连续式)Nd:YAGLaser(CW)Lasers19Nd:YAG激光(半导体激光激发)Nd:YAG(LDPumped)Lasers20染料激光DyeLasersPage7激光用元件LASERCOMPONENTS1Q开关LaserQ-Switches2激光管LaserTubesandBores3激光棒LaserRods4激光护眼镜SaftyEquipment;GogglesGlassesandFilms5气体再生设备，气体填充设备GasRecyclersandGasHandlingEquipment6激光控制设备LaserControlEquipment7激光用共振腔ResonatorsforLasers8激光用冷却设备CoolingSystemsforLasers9激光用安全设备SaftyEquipment;ProtectiveHousingsPage8Text2OpticalResonator1Theradiationemittedbymostlaserscontainsseveraldiscreteopticalfrequencies,separatedfromeachotherbyfrequencydifferenceswhichcanbeassociatedwithdifferentmodesoftheopticalresonator.Eachmodeisdefinedbythevariationoftheelectromagneticfieldperpendicularandalongtheaxisoftheresonator.大多数激光器发射的光都包含有几种分立的光学频率，它们彼此间的频率差各不相同，从而使光学谐振腔产生不同的模式.Page92Itiscommonpracticetodistinguishtwotypesofresonatormodes:“Longitudinal”modesdifferfromoneanotheronlyintheiroscillationfrequency;“transverse”modesdifferfromoneanothernotonlyintheiroscillationfrequency,butalsointheirfielddistributioninaplaneperpendiculartothedirectionofpropagation..通常将谐振腔产生的模式分为两类:“纵模”与“横模”，纵模彼此间的差异仅在于它们具有不同的振荡频率;横模彼此间的差异除了具有不同的振荡频率外，而且在垂直于其传播方向的平面内，场的分布也不同。Page103ThesymbolsTEMmnqandTEMplqareusedtodescribethetransverseandlongitudinalmodestructureofawaveinsidetheresonatorforrectangularandcylindricalcoordinates,respectively.Thecapitallettersstandfor“transverseelectromagneticwaves”andthefirsttwoindicesidentifyaparticulartransversemode,whereasqdescribesalongitudinalmode.人们用符号TEM来描述光学谐振腔内电磁场的变化.大写字母TEM表示“横向电磁波”，前两个下标表示特定的横模，q表示纵模，Page114Becauseresonatorsthatareusedfortypicallasersarelongcomparedtothelaserwavelength,theywill,ingeneral,havealargenumberoflongitudinalmodes.Therefore,theindexqwhichspecifiesthenumberofmodesalongtheaxisofthecavitywillbeveryhigh.Theindicesforthetransversemodes,whichspecifythefieldvariationsintheplanenormaltotheaxis,areverymuchlowerandtypicallymaybeonlythefirstfewintegers.因为典型激光器所用的谐振腔都比激光波长要长得多，所以一般都有很多纵模.因此，表示腔体轴向模数量的q的数值非常大.表示横模的下标值却很小，有时可能只取前几位整数.。Page125Althougharesonatormodeconsistsofatransverseandaxialfielddistribution,itisusefultoconsiderthesetwocomponentsseparatelybecausetheyareresponsiblefordifferentaspectsoflaserperformance.Thespectralcharacteristicsofalaser,suchaslinewidthandcoherencelength,areprimarilydeterminedbythelongitudinalmodes,whereasbeamdivergence,beamdiameter,andenergydistributionaregovernedbythetransversemodes.激光器的光谱特性，如谱线宽度和相干长度等，主要取决于纵模;而光束发散角、光束直径和能量分布等则取决于横模，Page136Ingeneral,lasersaremultimodeoscillatorsunlessspecificeffortsaremadetolimitthenumberofoscillatingmodes.Thereasonforthisliesinthefactthataverylargenumberoflongitudinalresonatormodesfallwithinthebandwidthexhibitedbythelasertransition,andalargenumberoftransverseresonatormodescanoccupythecrosssectionoftheactivematerial.一般来说，如果没有采取特殊的措施来限制振荡模的数量，激光器就是多模振荡器。其原因在于这样的事实，即非常多的谐振腔纵模都处于激光跃迁的带宽内，而在激活材料的截面内，可能有很多横模.。Page147IntensityDistributionInanopticalresonator,electromagneticfieldscanexistwhosedistributionofamplitudesandphasesreproducethemselvesuponrepeatedreflectionsbetweenthemirrors.Theseparticularfieldconfigurationscomprisethetransverseelectromagneticmodesofapassiveresonator.那些在两个反射镜之间来回反射，其振幅和相位分布保持不变的电磁场才能够存在于光学谐振腔中.这些特殊的场分布形成无源谐振腔的横电磁模.Page153.Exercise1、TransversemodesaredefinedbythedesignationTEMmnforCartesiancoordinates.Theintegersmandnrepresentthenumberofnodesofzerosofintensity.Inylindricalcoordinates,themodesarelabeledTEMplandareharacterizedbythenumberofradialnodespandangularnodesl.在直角坐标系中，用符号TEM表示横模，整数m和n表示在水平和垂直方向上与光轴垂直的强度零节点的数量.在圆柱坐标系中，用TEMpl表示横模，p表示径向节点数，l表示角向节点数.Page162、Thehigherthevaluesofm,n,p,andl,thehigherthemodeorder.ThelowestordermodeistheTEM00mode,whichhasaGaussianintensityprofilewithitsmaximumonthebeamaxis.Formodeswithsubscriptsof1or1more,intensitymaximaoccurthatareoff-axisinasymmetricalpattern.m,n,p,andl的数值越大，模的阶数就越高.最低阶模是TEN00模，在它的光袖上有最大的高斯强度分布，对于下标为1或比1大的模。最大的强度值不在对称花样的袖上.Page17Page1819感谢您的学习