科技英语翻译哪位大虾帮下忙!急用的很!,先谢过拉!

科技英语翻译哪位大虾帮下忙!急用的很!,先谢过拉!
A schematic depiction of the organization of an archetypical optical system is given in Figure 12.1. The model used here, as we will see in the subsequent discussion, is quite general and applies to practically all-optical systems that exist, including communications as well as sensing systems. For example, the earliest types of optical communication systems were probably ones in which a lamp was sequentially hidden from sight for fixed periods between periods of being in plain view. Such a system was employed by Paul Revere in 1776, but it is very likely that such systems had been in operation since the times of the early Greeks or Egyptians . In such a system, the information source is the lamp holder, the encoder is his arms together with the occluding sheet, the receiver optics are the eyes of the beholder, the detector is the beholder's retinae, the receiver is the brain of the beholder, and the information out is the response of the beholder. One could say that such a system employs digitally encoded on-off keyd intensity modulation with direction detection (a DEOOKIMDD or DIM system, depending on the receiver design ) if one were to classify this system. A similar block diagram description could apply to an Indian on a hill sending smoke signals back to his tribe a fiber optic gas detection system, a telescope, or, as we will see as we go on, practically any optical system we can devise.
Perhaps a major point in having a model such as in Figure 12.1 is that such a model is so general that we can use it as a basis for comparing widely differing systems that at first may appear incomparable. Certainly, however, any tow systems can be compared by comparing the data launched into the system with that exit the system (bit error rate (BER) counting in digital systems or noise figure measurement in analog systems). Other figures of merit can, indeed, also allow comparison of the specific blocks of the model. Such comparison will be a major occupation of this course - to compare performance of the various schemes for performing the various functions of the blocks of Figure 12.1. The following four subsections will discuss first sources, then fibers, and then detectors. The last section will give some systems architecture perspective, as the other types of components which make up the blocks of Figure 12.1 in the archetypical "modern-day" optical communication systems are very architecture-dependent. The discussion that follows will be given from a somewhat historical perspective.
Optical Paths
The second major development to occur during 1970 was the development of the low loss optical fiber. The idea of communicating through free space is well and good, but as was previously stated, a major advantage of optical transmitters was their directivity. For broadcasting, it is hard to beat radio waves.For point to point, it is hard to beat optics. But there are problems with using free space as a transmission medium.

1示意图描绘本组织的一个原型的光学系统,给出了在数字12.1 .所用的模型在这里,正如我们将看到在随后的讨论中,是相当普遍适用于几乎所有光学系统中存在的,包括通讯,以及传感系统.举例来说,最早类型的光纤通信系统可能是,在其中一盏灯,是按顺序从隐藏的视线固定期之间的时期,正处于平原的看法.这样一个系统是受雇于保罗里维尔在1776年,但它是很可能,这种系统以来一直在运作的时代早期希腊人或埃及人.在这样一个制度,信息来源是灯座,编码是他的武器同咬牙资产负债表,接收器光学是眼睛的beholder ,探测器是beholder的视网膜,接收机是脑的beholder ,和信息是反应的beholder .人们可以说,这种系统采用数字编码就小康keyd强度调制与方向检测（一deookimdd或黯淡的制度,这取决于接收器的设计） ,如果一被归类这个制度.类似的框图描述能适用于印度对一宗山火,发送烟雾信号回到他的部落光纤气体侦测系统,望远镜,或者,如我们将看到我们下去,几乎所有的光学系统,我们可以制定.
也许是一大点,有一个模型,如在1月12日的数字是,这种模式一般是这样,我们可以使用它来作为一个基础广泛的比较,不同的系统,首先可能出现的无与伦比的.当然,不过,任何拖车系统进行比较,可以比较的数据发射到该系统与退出系统（误码率（ BER ）的计数数字系统或噪声系数测量中的模拟系统） .其他的数字,值得可以,事实上,也允许比较具体的基石模型.这种比较将是一个重大的占领,这当然是-比较性能的各项计划,为履行各项职能的座数字1 2.1.以下四个小节将讨论的第一来源,那么,纤维,然后探测器.最后一节将提供一些体系结构的角度来看,作为其他类型的组成部分弥补块的数字,1月12日在原型“现代-天”光通信系统是非常架构的依赖.以下的讨论会考虑从一个有点历史的角度来看.
光路
第二个大发展,以发生在1970年是发展的低损耗光纤.的思想沟通,通过自由空间,以及和好的,但正如先前指出,一个主要的优势光学发射机是他们的方向性.广播,是很难击败电台waves.for点对点,是很难击败光学.但有问题,使用免费空间作为传输介质