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1、,Laser English,LOGO,Page 2,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,Page 3,1、New Words and phrases,1、Wavelength 波长 2、Power 功率 3、Beam Quality 光束质量 4、Beam Diameter 光斑直径 5、Divergence 发散角 6、Power Stability 功率稳定性 7、Power supply 电源输入 8、cooling system 冷却方式 9、near TEM0
2、0 近基模 10、Output power 输出功率 11、Repetition frequency 脉冲重复频率,Page 4,12、Pulse width 脉宽 13、Space mode 空间模式 14、Diode-pumped 二极管泵浦 15、Specification 规格、说明书,Page 5,气体激光 GAS LASERS 1 氦氖激光 He-Ne Lasers 2 金属蒸气激光 Metal Vapor Lasers 3 氩离子激光 Argon Lasers 4 氪离子激光 Krypton Lasers 5 二氧化碳激光(气流型) CO2 (Gas Flow type) Las
3、ers 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 (Sealed tube) Lasers 8 二氧化碳激光(波导型) CO2 (Wave guide) Lasers 9 一氧化碳激光 CO Lasers 10 氦镉激光 He-Cd Lasers 11 氮分子激光 Nitrogen Lasers,Page 6,12 准分子激光 Excimer Lasers 13 氙分子激光 Xenon Lasers 14固体激光 SOLID STATE LASERS 15 红宝石激光 Ruby Lasers 16半导体激光(0.60
4、m 带) Semiconductor (0.60m) Lasers 17 Nd:YAG 激光(脉冲式) Nd:YAG (Pulsed) Lasers 18 Nd:YAG 激光(连续式) Nd:YAG Laser (CW) Lasers 19 Nd:YAG 激光(半导体激光激发) Nd:YAG (LD Pumped) Lasers 20染料激光 Dye Lasers,Page 7,激光用元件 LASER COMPONENTS 1 Q 开关 Laser Q-Switches 2 激光管 Laser Tubes and Bores 3 激光棒 Laser Rods 4 激光护眼镜 Safty Equ
5、ipment; Goggles Glasses and Films 5 气体再生设备，气体填充设备 Gas Recyclers and Gas Handling Equipment 6 激光控制设备 Laser Control Equipment 7 激光用共振腔 Resonators for Lasers 8激光用冷却设备 Cooling Systems for Lasers 9激光用安全设备 Safty Equipment; Protective Housings,Page 8,Text 2 Optical Resonator,1 The radiation emitted by most
6、 lasers contains several discrete optical frequencies,separated from each other by frequency differences which can be associated with different modes of the optical resonator. Each mode is defined by the variation of the electromagnetic field perpendicular and along the axis of the resonator. 大多数激光器
7、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.,Page 9,2 It is common practice to distinguish two types of resonator modes: “Longitudinal” modes differ from one another only in their oscillation frequency; “transverse” modes differ from one another not only in their oscillation frequency, but also
8、in their field distribution in a plane perpendicular to the direction of propagation. . 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。,Page 10,3 The symbols TEMmnq and TEMplq are used to describe the transverse and longitudinal mode structure of a wave
9、 inside the resonator for rectangular and cylindrical coordinates, respectively. The capital letters stand for “transverse electromagnetic waves” and the first two indices identify a particular transverse mode, whereas q describes a longitudinal mode. 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
10、特定的横模，q表示纵模，,Page 11,4 Because resonators that are used for typical lasers are long compared to the laser wavelength, they will, in general, have a large number of longitudinal modes. Therefore, the index q which specifies the number of modes along the axis of the cavity will be very high. The indic
11、es for the transverse modes, which specify the field variations in the plane normal to the axis, are very much lower and typically may be only the first few integers. 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.。,Page 12,5 Although a resonator mode consists of a t
12、ransverse and axial field distribution, it is useful to consider these two components separately because they are responsible for different aspects of laser performance. The spectral characteristics of a laser, such as line width and coherence length, are primarily determined by the longitudinal mod
13、es, whereas beam divergence, beam diameter, and energy distribution are governed by the transverse modes. 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，,Page 13,6 In general, lasers are multimode oscillators unless specific efforts are made to limit the number of oscillating modes. The reason
14、 for this lies in the fact that a very large number of longitudinal resonator modes fall within the bandwidth exhibited by the laser transition, and a large number of transverse resonator modes can occupy the cross section of the active material. 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
15、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.。,Page 14,7 Intensity Distribution In an optical resonator, electromagnetic fields can exist whose distribution of amplitudes and phases reproduce themselves upon repeated reflections between the mirrors.These particular field configurations comprise the transvers
16、e electromagnetic modes of a passive resonator. 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.,Page 15,3.Exercise,1、Transverse modes are defined by the designation TEM mn for Cartesian coordinates. The integers m and n represent the number of nodes of zeros of intensity . In ylindrical coordinates, the modes are labeled TEMpl and are
