专业英语教案 光电信息工程专业用

1、.专 业 英 语 教 案.1 What is Optics（什么是光）Mankind has always been fascinated with light, thinking of it in ancient times as an uncontrollable, mystical force of nature. Science unraveled some of its mysteries as the inventions of mirrors, spectacles, and later microscopes and telescopes revealed to mankind

2、 how light can be tailored to help people in their daily lives and in exploration, physically through the world and intellectually through science. u unraveled vt. 阐明, 解决u reveal vt. 展现, 显示, 揭示, 暴露u tailor n. 裁缝；vt. 剪裁, 缝制(衣服), 适应, 适合人类总被光迷住，在古代把它认为成是一种无法控制的、神秘的自然力量。科学用一些发明来阐明光的神秘，例如有镜子，眼镜和后来展示给人类的显

3、微镜和望远镜，以此来告诉我们光是如何被调整而用于帮助人们的日常生活和科学研究，以及帮助我们认识世界和发展科学（身体上通过世界和智力通过科学）。Optics is the study of light and vision in science and engineering. Light is generally defined as the sector of the electromagnetic spectrum between the infrared and ultraviolet sectors that can be seen with the unaided eye.光学是在科

4、学和工程方面对光和视觉的研究。光一般被定义介于红外和紫外之间、可被裸眼看到的电磁波谱的一部分。Optics plays an influential role in our lives:光学在我们的生活中起着重要作用：When you look into a mirror in the morning to comb your hair, when you see a rainbow after it rains, in medical devices that save lives, as you read this page, as you see, optics is at work.当

5、你在早晨面对一面镜子梳你的头发时，当你在雨后看到彩虹时，在那些挽救生命的医学设备里，当你读这篇文章时，如你所见，是光在工作。Through these lessons, we hope to give you at least a peeku peek vi. 偷看；窥视；偷偷的一看, 一瞥我们希望通过下面的这些课程，可以使你对光学有个大概的了解：into geometrical optics; u geometrical adj. 几何学的, 几何的对几何光学into physical optics; 对物理光学into the dual nature of light and past a

6、nd current theories on it; 光学在过去和现代理论中的二重性into lenses and mirrors; 对透镜和反射镜into optical instruments; 对光学仪器into experiments that led to breakthroughs in the study of optics; u breakthrough n. 突破；突破性的发现，成就对在光学的研究过程中带来突破的实验；into how optics affects our daily lives and how it will affect the future.光学是如何影

7、响我们现在的日常生活，以及将如何影响未来。2 The Dual Nature of Light（光的二重性）The nature of light has been a controversy debated throughout the course of history. Two models evolved: the wave model and the particle model. Each model has taken an important dominating place, but neither has been disproved completely. Therefo

8、re, the scientific community has combined the two theories to form the wave particle duality, where characteristics from both models are attributed to light (the “wavicle”). These two seemingly contradicting models have been reconciled by a new theory of physics, called quantum electrodynamics, whic

9、h is a quantum theory of the electromagnetic interactions between photons, electrons and muons (an elementary particle having a mass around 200 times greater than an electron). This model is also known as quantum theory of light. u controversy n. 争论, 辩论, 论战；u debate v. 争论, 辩论u dominating adj. 专横的, 主

10、要的, 独裁的u disprove vt. 反证；反驳；证明为伪u wavicle 物量子波粒二象性u attribute vt. （与to连用）归因于u contradict vt. 同矛盾, 同抵触u reconcile vt. 使和解, 使和谐, 使顺从；调解, 调停; 使相协调u quantum electrodynamics n. 物量子电动力学u electromagnetic interaction 电磁相互作用u muon n. 介子u elementary particle n. 核基本粒子光的本性在其整个历史过程中是一场辩论。它们发展成两种模式：波动模型和粒子模型。每一种模

11、型都有其重要的专用位置，但是没有任何一个可以被完全证明为误。因此，科学界将这两种理论结合而形成波粒二象性，而来自于两种模型的特征可以归因于光（波粒二象性）。这两种看似矛盾的模型被一种新的物理理论所统一，即量子电动力学，是一种光子，电子和介子（某一体积比单个电子大大约200倍的基本粒子）之间的电磁相互作用的量子理论。这个模型也被称为光的量子理论。The Wave Theory of Light:光的波动理论The theory that light is transmitted via wave form was proposed by Christian Huygens in 1679. Ac

12、cording to his theory:光以波动形式传播的理论是克里斯蒂安惠更斯在1679年提出的，根据他的理论：（克里斯蒂安惠更斯：（Christian Huygens 1629-1695）是与牛顿同一时代的科学家，是历史上最著名的物理学家之一，他对力学的发展和光学的研究都有杰出的贡献，在数学和天文学方面也有卓越的成就，是近代自然科学的一位重要开拓者。）l Light must travel through a medium. 光必须通过某种介质进行传播。l This medium is called Ether, which is an omnipresent, boundlessly

13、 resilient, massless medium unable to be sensed that was formerly theorized as the medium that carried light. 这种介质称为以太，它是一种无所不在的，有无限弹性的，无质量的，不不能被感知的介质，在从前它被理论化为能运载光的介质。l Light is a form of energy - Light travels in waveform in short wavelengths. 光是一种能量形式光在短波长方面以波形的形式传播。u ether n. 天空醚, 大气, 苍天, 物以太u o

14、mnipresent adj. 无所不在的, 同时遍在的u boundlessly adv. 无穷地, 无限地u resilient adj. 弹回的, 有回弹力的u massless adj. 物无质量的u theorize v. 建立理论, 理论化u waveform n. 波形The Particle Theory of Light:光的粒子理论The theory that light is transmitted via corpuscular form was supported and advocated by Sir Isaac Newton. According to thi

15、s theory: light is composed of particles (“corpuscular”) that travel in a straight line at an extreme speed, they allow the eye experience vision when they are absorbed, and various colored particles all have differing sizes.u corpuscular adj. 微粒的，细胞的，小体的u advocate vt. 拥护；提倡； 主张u according to v. 依照光

16、以粒子形式传播的这一理论被艾萨克牛顿先生支持并且提倡。依照这一理论：光是由粒子构成的，它们沿直线并以高速传播，当它们被吸收时，就使得眼睛体验视力，不同颜色的粒子都有着不同的尺寸。The Quantum Theory of Light:光的量子理论The theory that combines both the wave and particle models was suggested by Max Planck. According to this theory: light is absorbed or released in bundles of energy called photo

17、ns. u suggest vt. 建议, 提出, 使想起, 暗示结合波动模型和粒子模型的理论是由马克斯普朗克提出的。依照这一理论：光被以含有能量束的光子形式吸收或者释放。Huygens Principle:惠更斯原理Christian Huygens, a Dutch scientist, supported the concept that light is a wave motion that is transmitted through ether. Applying this theory, Huygens derived the laws of reflection and ref

18、raction.u derive vt. 获得, 导出(from)克里斯蒂安惠更斯，一位荷兰科学家，他支持光是通过以太传播的波形运动的概念。应用这一理论，惠更斯推导出反射定律和折射定律。Youngs Double-Slit Experiment:杨氏双缝实验Thomas Young (1773-1829), an English scientist, also credited for helping translate the Rosetta Stone, conducted an experiment in 1801, known as Youngs double-slit experim

19、ent, that allowed him to show the wave nature of light and measure its wavelengths. The setup of this experiment is quite elegant-Light from a single source shines through two narrow, closely-placed slits for them to serve as two coherent light sources. (A coherent light source is one that makes lig

20、ht waves have a consistent phase relationship with each other-crest overlaps crest, trough overlaps trough) A screen is put behind these slits.u credit n. 信任, 信用, 声望, 荣誉, 财务贷方, 银行存款vt. 相信, 信任, 把.归给u conduct vt. 处理； 经营；引导；实施u elegant adj. 优雅的, 风雅的, 雅致的, 文雅的, 有风度的；优美的, 精彩的, 讲究的u crest 【物】波峰; 振幅; 峰值, 最

21、大值u trough 【物】波谷托马斯杨(1773-1829)，一位英国科学家，也相信可以帮助翻译“罗塞塔碑”，在1801年进行了一个实验，就是著名的“杨氏双缝实验”，这一实验使得他向人们展示了光的波动特性，并且可以测量波长。这个实验的安装十分讲究来自同一光源的光将两条狭窄、挨得很近的裂缝照亮，那么它们就象两个相干光源（相干光源是指能够使得两束光相互有固定的位相关系，波峰与波峰重叠，波谷与波谷重叠）。（约5000年前，古埃及人发明了一种图形文字，称为象形文字。这种字写起来既慢又很难看懂，国此大约在3400年前，埃及人又演化一种写得较快并且较易使用的字体。随着时光的流逝，最终连埃及人自己也忘记了

22、如何释讳早期的那种象形文字了。若不是因为拿破仑大军入侵埃及时，随军的法国古文字学家们的那次发现，极有可能至今考古学家们仍无法辩认这种文字。年，拿破仑率军远征埃及时，他手下的一名军官布夏尔带领士兵，在罗塞塔城附近修筑防御工事时，发现了一块黑色玄武岩断碑。碑上用两种文字三种字体刻着同一篇碑文。最上面用的是古埃及的象形文字，中间是古埃及的草书体象形文字（亦称民书体文字），下面是希腊文字。这就是后来被世人称之为“罗塞塔碑”的著名石碑。原来，“罗塞塔碑”上的碑文是公元前年埃及孟斐斯城的僧侣们，给当时的国王写的一封歌功颂德的感激信。这位国王就是第十五王朝法老托勒密。他登上国王宝座后不久，取消了僧侣们欠交的

23、税款，并为神庙开辟了新的财源，对神庙采取了特殊的保护措施，给僧侣们带来了一系列好处，所以很快赢得了僧侣们的敬仰。于是僧侣们写了这封感激信，并用三种字体写的两种文字刻在这块黑色玄武岩碑石上。小小的罗塞塔城，由于有了这块借以解开埃及象形文字之谜的碑石而举世闻名。不过，这块著名的碑石早已不在该城，它被收藏在伦敦的大英博物馆里了。）Now, if light consisted of particles, then the screen would reveal two bright lines when the light illuminated through. Young, however, s

24、aw a center bright line and groups of symmetrical dark and bright edges and explained these groups to be marks of constructive and destructive interference. u constructive interference 相长干涉（当两列同相的波相遇，它们的波峰波谷会叠加成一个更大的波峰波谷，这现象称为相长干涉。）u destructive interference 相消干涉（当两列反相的波相遇，一列波的波峰会叠加在另一列波的波谷上，使两个波互相抵

25、消，这现象称为相消干涉。）那么，若光由粒子组成，当光通过狭缝时，在屏幕上将显示两条明亮的线。不过，（托马斯）杨看见中心是亮线，然后两侧是对称的明暗边缘，并且解释这些条纹就标志着相长干涉和相消干涉。So, since weve covered the basics, here is a diagram, which geometrically analyzes the experiment and explains some equations:因此，既然掌握了这些基本性质，这就是一张图解，可以从几何角度分析这些实验并且解释一些方程式：As the image indicates, the di

26、fference in the length of and is .正如图像所显示的，和的长度差为。Equations for Youngs Double-Slit Experiment may be found here. 杨氏双缝实验的公式在这里就可以得到。Fresnel and Transverse Waves:Augustin Fresnel, in 1821 put forward results from experiments involving double refraction and polarized light suggested that light is a tra

27、nsverse wave, which is a wave where the vibrating part moves perpendicularly to the coming wave. Equations that he formulated, the Fresnel equations provide the amplitude of reflected and transmitted polarized light traveling at a plane interface. u Transverse adj. 横向的, 横断的u formulate vt. 用公式表示, 明确地

28、表达, 作简洁陈述；v. 阐明u amplitude n. 【物】振幅u interface n. 分界面奥古斯丁菲涅耳，在1821根据双折射和偏振光方面的实验提出结论，认为光是一个横波，所谓横波是指波的振动方向与传播方向垂直（原文：波的振动部分垂直地移向来波）。他推导出的方程式称为菲涅耳方程式，当光遇到一个平面的分界面时，它可以给出反射光和透射偏振光的振幅。Further Developments:James Clerk Maxwell, a scientist studying electricity and magnetism, formulated the four Maxwell e

29、quations, which gave a predicted speed of an electromagnetic wave through ether, which actually ended up being the speed of light, c. So from this point on, light was considered to be a part of the electromagnetic spectrum.u Predict v. 预知, 预言, 预报, 预测u end up v. 竖着, 结束, 死詹姆斯克拉克麦克斯韦，一位研究电学和磁学（电磁学）方面的科

30、学家，总结出4个麦克斯韦方程式，这一方程组可以给出电磁波在以太中的预测速度，这实际上是给出了光速c。因此自此以后，光被认为是电磁波谱的一部分。And later still, Einsteins theory of relatively helped throw out the idea of ether, which solved some problems dealing with the transverse vibrations of waves in liquids and gases.u throw out v. 伸出, 扔掉, 说出, 派出, 放出, 使出局, 使突出, 显示并且

31、直至后来，爱因斯坦的相对论帮助（我们）丢弃以太的概念，这就可以解决在液体和气体中横波遭遇的一些（无法解决的）问题。3 Geometrical Optics（几何光学）Lets face it. Optics is pretty complicated. Light travels in waves, and waves are not easy to analyze. Thats why in this lesson we are going to try to explain as many phenomena of reflection and refraction as possible

32、 with only straight lines and angles instead of waves to represent light. 让我们面对它。光学相当错综复杂。光以波的形式传播，而波也不容易分析。那也就是为什么在这门课中，我们将尽可能多地只用直线和角度而非波来描述反射和折射现象。Before we begin, an important concept to note is the speed of light, or .在我们开始之前，需要要注意到的一个重要的概念，那就是光的速度，或者叫。Now that you know the speed of light in me

33、ters per second, you will be able to apply it to many calculations that you may come across in geometrical optics and beyond. The two major phenomena in geometrical optics are reflection and refraction, both of which we will not go into extreme detail in this lesson.u come across v. 来到, 偶遇；不期而遇, 交付u

34、 geometrical adj. 几何学的, 几何的既然你知道光速达到每秒米级，你将能把它用于你可能在几何光学方面和其他方面遇到的许多计算问题。在几何光学中，两个主要的现象就是反射和折射，在这一课程里，我们将不作详细的叙述。Wave Fronts and Rays波前和光线Waves, whether it is electromagnetic or other, are conveniently described in terms of wave fronts. A wave front is the line or surface defined by adjacent portion

35、s of a wave that are in phase. -If an arc is drawn along one of the crests of a circular water wave moving out from a point source, all the particles on the line will be in phase. u wave front 波前, 波阵面u in phase 【物】同相的地；同时协调的地u draw vt. 拉, 拖, 拉拖长, 拉成(丝等);描(图), 绘制, 画(线), 勾(轮廓) 波，不论它是电磁的还是其它的，通常用波前来描述。

36、波前是指一个波邻近部分的线或面，它们是同相的。如果一个光弧是沿着一个由点光源发出的圆形水波的振幅勾勒而成的，那么圆弧线上的所有点将是同相位的。The curvature of a short segment of a spherical or circular wave front is small. The segment may be approximated as a linear wave front or a plane wave front, just as we assume the surface of the Earth to be locally flat. 球面波前或圆波

37、前中的一小部分的曲率是小的。这一部分可以近似地认为是线性波前或平面波前，正如我们假设地球表面的局部是平的一样。In a uniform medium wave fronts propagate outward from the source at a wave speed characteristic of the medium. For example, the speed of light travels fastest in a vacuum: .在同一介质中，波前以与光源发出的光同样的介质波速特性向外传播。例如，光的速度在真空中传播最快，为。The geometrical descri

38、ption of a wave in terms of wave fronts tends to neglect the fact that the wave is actually sinusoidal. The concept of a ray simplifies the wave description even further. A ray is a line drawn perpendicular to a series of wave fronts and pointing in the direction of propagation. A beam of light can

39、be simplified and represented by a group of parallel rays or just a single ray. u in terms of adv.根据, 按照, 用.的话, 在.方面u sinusoidal adj. 正弦曲线, 窦状小管, 窦状隙u simplify vt. 单一化, 简单化u description n. 描写, 记述, 形容, 种类, 描述u perpendicular adj. 直的, 正交的u represent vt. 代表, 象征u parallel adj. 平行的, 相同的, 类似的, 并联的；n. 平行线,

40、平行面, 类似, 相似物用波前的概念对光波进行几何描述，趋向于忽略波是正弦曲线这一事实。一条光线的概念简化为波的描述，甚至更进一步。一条光线是一条被描述成垂直于一系列波前，并且沿着传播方向的直线。一束光可以被简化并且描述为一组平行的射线或仅仅一条光线。Reflection and Refraction反射和折射We said that we are only going to talk about light in terms of straight lines and rays in this lesson; we lied. For the most part, we are still

41、going to talk about light in terms of straight lines and rays in this lesson, but to explain the concept of reflection, we will need to talk a little bit about the electromagnetic waves that compose light.我们说在这门课中我们将只用直线和射线的方式谈论光；我们说谎了。在绝大部分场合，我们将继续以直线和射线的方式谈论光，但是为了解释反射的概念，我们将需要探讨一点儿光用电磁波谱描述的情形。The

42、two most important methods of light propagation are reflection and refraction. Reflection involves the absorption and re-emission of light by means of complex electromagnetic vibrations in the atoms of the reflecting medium. Refraction refers to the change in direction of a wave at a boundary where

43、the wave passes from one medium into another. 光的两种最重要传播方式是反射和折射。反射包含光的吸收和在反射介质的原子中光以电磁波动的形式重新发射光的两种情形。折射是指当光从一种介质进入另外一种介质时，在其界面处波传播方向发生变化的情形。A light ray incident on a surface is described by an angle of incidence. This angle is measured relative to a line perpendicular, or normal, to the reflecting

44、surface. Likewise, the reflected ray is described by an angle of reflection. This relationship between these angles is given by the law of reflection:一条光线入射到一个表面上被描述成入射角。这一角度是指相对于反射表面垂直或正交的直线所成的角度。同样地，反射光线被描述为反射角。这两个角度的关系可用反射定律给出：。The angle of incidence is equal to the angle of reflection.入射角等于反射角。T

45、ypically when a ray strikes a smooth surface separates two different transparent mediums (i.e. air and water) part of the ray is reflected and part of the ray is refracted. or transmitted into the second medium. There are two forms of reflection: specular reflection, which entails the reflection at

46、a definite angle from a very smooth surface, and scattered reflection, which entails the reflection at various different angles. Both forms of reflection may occur in either opaque or transparent materials. Refraction is the light propagation where the transmitted light passes through two transparen

47、t mediums and consequently changes its direction. An index of refraction or refractive index of an optical material, denoted by n, is the ratio of the speed of light, c, in vacuum to the speed v in the material.u strike vt.到达u entail vt. 需要；使承担u definite adj. 明确的, 一定的u opaque adj. 不透明的, 不传热的, 迟钝的u t

48、ransparent adj. 透明的, 显然的, 明晰的u pass through v. 经过, 通过u denote vt. 指示, 表示通常，当光到达两种不同透明介质的光滑表面时，一部分光被反射，另一部分被折射，或者说传播到第二种介质中。有两种反射形式：镜面反射，是指从一非常光滑表面以一定角度发生的反射；漫反射，是指向多个不同角度发生的反射。两种方式的反射均可在不透明或透明的材料上。折射是指当（传输的）光波通过两种透明介质时光的传播，而且改变了它的传播方向。光学材料的折射率用n表示，是真空中光速c与材料中光速v的比值。(index of refraction) 折射率The index

49、 of refraction of an optical material (also called the refractive index) denoted by n above, plays a central role in geometric optics. It is the ratio of the speed of light c in vacuum to the speed v in the material. 光学材料的折射率用上面的n表示，它在几何光学中占有很重要的地位。它也等于真空中光速c与在介质中光速v的比值。Wave speed v is inversely pro

50、portion to the index of refraction n. The greater the index of refraction in material, the slower the wave speed in that material. Failure to remember this point can lead to hopeless confusion! u inversely adv. 相反地, 倒转地u proportion n. 比例, 均衡, 面积, 部分u confusion n. 混乱, 混淆光速v与折射率n成反比。材料的折射率越大，光速在其中的速度越

51、慢。忘记这一点可能导致没希望的混乱！The Laws of Reflection and Refraction反射定律和折射定律1. The incident, reflected and refracted rays and the normal to the surface all lie in the same plane.入射，反射，折射和表面的正交线都在同一平面内。2. The angle of reflection is equal to the angle of incidence for all wavelengths and for any pair of materials

52、. 对所有波长和任何一对材料来说，反射角等于入射角。3. The ratio of the sines of the angles, and , where both angles are measured from the normal to the surface, is equal to the inverse ratio of the two indexes of refraction: and 正弦的比值等于两种折射率的反比，而两个角度都是从正交线向表面方向测量。OR 或 (law of refraction) 折射定律This experimental result, togeth

53、er with the observation that the incident and refrated rays and the normal all lie in the same plane, is called the law of refraction or Snells law, after the Dutch scientist Willebrord Snell.这个实验结果， 事件和refrated 射线和正常的全部谎话在相同飞机内的以及观察， 被叫为折射定律或者斯内尔的法律，在荷兰科学家Willebrord斯内尔之后。Total Internal Reflection:A

54、ccording to Snells law, the larger the angle of incidence, the larger the angle of refraction, or the greater distance the refracted ray diverges from the norm.u diverge v. 偏离；背离：根据斯内尔的定律，入射角越大，折射角也越大，或者说折射线越偏离正交线。There is a restraint to this divergence, however. With a particular angle of incidence

55、 called the critical angle, the resulting angle of refraction is 90 degrees. This angle carries the refracted light ray along the boundary between the two mediums involved in the refraction. If the angle of incidence is greater than the critical angle, or in other words, if the angle of refraction i

56、s greater than 90 degrees, the light is internally reflected. This state is known as total internal reflection.u restraint n. 抑制, 制止, 克制u carry vt. 表达，包含，意味u boundary n. 边界, 分界线u involve vt. 包括，涉及u in other words adv. 换句话说u internally adv. 在内, 在中心；内在的; 固有的u total internal reflection 光全内反射然而，对于这种偏离是有

57、限制的。对于称为临界角的特殊入射角，其折射角为90度。这一角度意味着折射光线沿着发生折射的两种介质的分界线射出。如果入射角比临界角大，或者换句话说，如果折射角大于90度，则光被全部反射。这种情形就被称为全内反射。The critical angle necessary for total internal reflection to occur can be found by plugging in 90 degrees for the angle of refraction and simplifying to the equation on the right.必然发生全内反射发生的临界角可在堵住90度折射角时发现，而且可以简化为下面的方程。Fiber Optics works on the principle of total internal reflection. Light travels along a fiber, reflecting off the walls at an angle greater than the critical angle due to the narrow, linear shape of the fiber. This c