【正文】 比，光纖更便宜，更細(xì)，更柔軟，不易燃，輕便，低功耗（因此對用于而言更便宜），可傳送更多的信息，信號的雜音和損失少。A Ray Relay光線繼電器A Fiber Optics system is like a relay of light rays. A fiber optics system usually consists of the following relay runners: transmitter, optical fiber, optical regenerator, and optical receiver. u relay runners接力賽跑運(yùn)動員u regenerator n. 再生器纖維光學(xué)系統(tǒng)看起來象光線繼電器。一個纖維光學(xué)系統(tǒng)通常包括以下組成部分：發(fā)送器，光纖，光學(xué)再生器和光接收器。First, the transmitter turns the light in a series of ons and offs. Thus this creates an almost Morse codelike signal that is sent through the optical fibers, often with the aid of a lens. The optical regenerator is not mandatory, but is very useful when transmitting light long distances, since often the light gets weakened by constant internal reflection. The regenerator dopes the light rays, or absorbs them with special doping optical fibers and spits them out again as stronger and clearer rays. The optical receiver is the last participant in the relay. It takes in the light rays using sensors called photocells and translates it into electrical signals, to be used in televisions or puters.u morse code 莫爾斯電碼；摩爾斯電碼u mandatory adj. 強(qiáng)制的,命令的, 托管的u dope v. 在...上涂料u doping (半導(dǎo)體)摻雜(質(zhì)), 加添加劑[填料]u spit vt., vi. 吐，吐出；吐口水u participant n. 參與者, 共享者u photocell n. 光電池首先，發(fā)送器將光轉(zhuǎn)換成一系列的“開”和“關(guān)”。如此，這就創(chuàng)造了一個類似莫爾斯電碼的信號，這樣的信號可以在透鏡的幫助下利用光纖傳輸。光學(xué)再生器不是必需的，但是當(dāng)長距離傳輸光時是非常有用的，因?yàn)楣饨?jīng)過不斷的內(nèi)部反射會減弱。再生器的作用是給光線上涂料，或者說是用特殊的添加劑使他們變強(qiáng)變清晰后發(fā)射出。光接收器是繼電器中的最后參加者。它使用稱為光電池的傳感器接受光線，將它們翻譯成電信號，以備在電視或電腦中使用。Getting into the Nooks and Crannies進(jìn)入隱蔽處或裂縫中One of the most useful characteristics of optical fibers is their ability to enter the minute passageways and hardtoreach areas of the human body. Fiber optics has made important contributions to the medical field, especially with regards to surgery. This has been acplished by cutting and polishing the ends of a very slim bundle of fibers, to form a fiberscope. The light is sent to the site of inquiry, reflected off of the area that the doctor wishes to see, and sent back to a receiver. Afterwards, the image is magnified to be analyzed. Because optical fibers are so flexible, they are able to navigate around the curvy parts of the human body in areas such as the stomach, heart, blood vessels, and joints. It is now even being possible to do surgery with instruments attached to the optical fibers, such as joint surgeries. Fiber optics is being especially important in heart surgery, since it can be done without disturbing the functioning of this delicate organ.u nook n. 隱蔽處u cranny n. 裂縫, 裂隙u minute adj. 微小的：異常小的，極細(xì)微的u passageway n. 過道, 出入口u cutting n. 切片, 切斷。 切削u polishing ，拋光u fiberscope n. 纖維內(nèi)窺鏡u site n. 地點(diǎn), 場所u inquiry n. 質(zhì)問；疑問u blood vessel n. 血管u joint n. 關(guān)節(jié)u disturb vt. 擾亂；攪亂；使騷動u functioning n. 機(jī)能u delicate adj. 病弱的, 脆弱的；靈敏的, 精密的u organ n. 器官光纖最有價值特性之一就是它能進(jìn)入微小的通道和人體很難到達(dá)的部位。纖維光學(xué)已經(jīng)對醫(yī)學(xué)領(lǐng)域做出重要貢獻(xiàn)，特別是外科手術(shù)。這已被完成，是通過切割和打磨一束非常細(xì)的光纖的末端，從而形成纖維內(nèi)窺鏡。光被送入有疑問的位置，然后反射回來的就是醫(yī)生想看到的部位，并被送回到接收器。然后，這幅圖像被放大以用來分析。因?yàn)楣饫w是如此的靈活，它能到達(dá)人體彎曲的部位，例如胃、心臟、血管和關(guān)節(jié)?，F(xiàn)在用附有光纖的儀器進(jìn)行外科手術(shù)已經(jīng)稱為可能，例如關(guān)節(jié)的外科手術(shù)。纖維光學(xué)在心臟手術(shù)中已顯示出重要性，因?yàn)樗梢圆淮騺y這一脆弱器官的機(jī)能。The Physics of Fiber Optics纖維光學(xué)物理性質(zhì)In physics, there is a phenomenon called refraction, where light bends upon entering medium with different indexes of refraction. There is a certain angle, called the critical angle, at which a light ray can enter the first medium and then travel between the two mediums, without crossing into the second medium. If the angle at which the ray passes through the first medium is greater than the critical angle, the ray will experience total internal reflection, where it will just reflect off the surface between the two mediums and reenter the first medium. This is the case with optical fibers. 在物理學(xué)里，有一種現(xiàn)象稱為折射，光彎折地進(jìn)入不同折射率的介質(zhì)。有一個角度，稱為臨界角，在此時，光線能返回第一種介質(zhì)，而后在兩介質(zhì)間傳輸，而不穿過第二種介質(zhì)。如果光線通過第一種介質(zhì)的角度大于臨界角，則光線發(fā)生全內(nèi)反射，而光線將在兩種介質(zhì)的表面上只發(fā)生反射，即光線重回第一種介質(zhì)。這就時光纖的工作原理。The glass core is the first medium that the light travels through. The cladding is the second medium, whose tangent surface to the core the light bounces off of. To picture it better, imagine two mirrors facing each other. The light bounces continually off each of them, getting absorbed be neither. In this case, the air acts as the core instead of glass. For optical fibers, the angle at which the ray passes through is always greater than the critical angle, thus causing no absorbance of light by the cladding. Any error that occurs or loss of signal is mainly because of impurities within the glass, which continually proves to be a problem in the field.u tangent adj. 切線的, 相切的u bounce v. 反跳, 彈起u in this case adv. 既然這樣玻璃核心是光線傳輸?shù)牡谝环N介質(zhì)。包層是第二種介質(zhì)，在其與內(nèi)核相切的表面處，光線反彈回去。為了更好地描繪，想象兩面彼此相對的鏡子。光線連續(xù)地在它們中間反彈，二者誰都不吸收。這樣的話，可用空氣作為核心而不是玻璃。對于光纖來說，光線傳輸?shù)慕嵌韧笥谂R界角，因此包層對光沒有任何吸收。出現(xiàn)的任何錯誤或者信號的損失主要是因?yàn)椴Ａ?nèi)的雜質(zhì)，在這一領(lǐng)域，這一直是個難題。5 Mirrors and LensesLenses and mirrors play important roles in our daily lives even though we may not notice them. Even now, as you are reading this, you are using the cornea lens in each eye and if you use eyewear such as contacts or glasses, you are also using those lenses to view this page. Recently you have probably seen your reflection in a mirror. In this lesson, we will explore different types of lenses and see how they impact vision.u eyewear n. 眼鏡u contacts n. 隱形眼鏡u reflection n. 映像透鏡和反射鏡在我們?nèi)粘Ｉ钪衅鹬浅Ｖ匾淖饔?，盡管我們可能沒有太注意它們。甚至現(xiàn)在，你正在看這個的時候，你正在使用角膜透鏡，并且即使是你戴了眼鏡，不論是隱形式的還是鏡片式的，你也同樣正在使用那些透鏡來看此文。最近，你可能在鏡子中看到了你的映像。在這一課中我們將會研究不同類型的透鏡，并且會發(fā)現(xiàn)它們是怎樣影響我們的視覺。First we will focus on mirrors, but before we go onto the specifics, here are a few basic terms that will help you throughout the section:u specifics n. 細(xì)節(jié)u term n. 術(shù)語首先我們來關(guān)注反射鏡，但是在我們具體研究之前，有一些基本的術(shù)語會幫助你理解這篇文章。Focal Point, Focal Length, Virtual Image, Real Image, Parallel ray, Radial ray, Focal ray焦點(diǎn)，焦距，虛像，實(shí)像，平行光，發(fā)射光線，會聚光線Now, that we got that straight, let39。s learn about the different types of mirrors and what kind of images they produce. There are two basic types of mirrors: plane