1. Good morning everyone! Now I'll begin my presentation about optical communication .
大家早上好！现在，我将开始我的关于光通信演示。
2. There are five parts in my report：
Definition，Classification，Optical Fiber Communication，Advantages and Disadvantages， Applications and Summary.
在我的报告有五个部分：定义，分类，光纤通信，优点和缺点，应用和总结。
3．Definition 定义
First we must know what are optical communications：
Optical communication is a form of long distance communication that uses light as the transmission medium.
首先我们要知道什么是光通信：光纤通信是远距离通信的一种形式，它利用光作为传输介质。
It consists of a transmitter, a channel and a receiver. 它包括一个发射器，一个信道和一个接收器。
4. Classification 分类
It can be divided several classifications: 它可以分为几个类别：
According to the different source characteristics : (1) laser communication (2) non laser communication 根据不同来源的特点： （1）激光通信 （2）非激光通信
According to the different transmission medium : (1) wired optical communications (2) wireless optical communication 根据不同的传输介质： （1）有线光通信 （2）无线光通信
5. Optical Fiber Communication 光纤通信
Let’s learn the ideal type : Optical Fiber Communication 让我们来学习理想的类型：光纤通信
Fiber-optic communication is a method of transmitting information from one place to another by sending pulses of light through an optical fiber. In China optical communication mainly refers to the optical fiber communication .
光纤通信是通过光纤发送的光脉冲从一个地方到另一个地方传输信息的方法。在中国光通信主要是指光纤通信。
A basic optical fiber communication system is composed of optical transmitter,
optical fiber cable, optical receiver.
一个基本的光纤通信系统是由光发送器，光纤光缆，光接收器的。
光纤通信是通过光纤发送的光脉冲从一个地方到另一个地方传输信息的方法。光形成被调制以携带信息的电磁载波。 Input electrical signal 输入的电信号 Optical transmitter 光发送器 Modulation 调制 Light source 光源
Optical fibre and cable 光纤光缆 Optical receive 光接收
Photoelectric detection 光电检测
Amplification and restoration 放大和恢复 注：红色汉字为PPT上翻译。
6. Optical Transmitter 光发送器
Convert the electrical signal into optical form and to launch the resulting optical signal into the optical fiber.
The most commonly used optical transmitters are semiconductor devices such as light-emitting diodes (LED) and laser diodes. 电信号转换成光形式将所得的光信号发射到光纤。
最常用的光发射器是半导体器件，例如发光二极管（LED）和激光二极管。
7. Optical Receiver 光接收器
Convert the optical signal received at the end of the optical fiber back into the original electrical signal.
The photodetector is typically a semiconductor-based photodiode.
在光纤的端部接收的光信号转换回原始电信号。光检测器是一个典型的基于半导体的光电二极管。
8. Advantages and Disadvantages 优点和缺点 Advantages:
1. Large capacity of communication; 2. Long distance relay; 3. Excellent security;
4. Small volume, light weight. 优点：
1，通信容量大; 2.中继距离长; 3.优异的安全性; 4.体积小，重量轻
9. Disadvantages:
1. Crispy texture, poor mechanical strength;
2. Shunt and coupling is not flexible;
3. Fiber optic cable bending radius cannot be too small; 4. Supply power is difficult. 缺点：
1.质地脆，机械强度差; 2.分流和耦合不灵活;
3.光纤电缆的弯曲半径不能过小; 4.供电是困难的。
10.Applications 应用
Space Communication 航天通信
Internet Communication 互联网通信 Optical Gyroscope 光纤陀螺仪
Optical Communications is used to send and receive information between ground and satellite. Optical fiber is used by many telecommunications companies to transmit telephone signals, Internet communication, and cable television signals. 光通信是用来发送和接收地面和卫星之间传输信息。光纤被许多电信公司传送电话信号，因特网通信和电缆电视信号。
Optical fibers can be used as sensors to measure strain, temperature, and other parameters. Optical fibers used as hydrophones for seismic or sonar applications. 光纤可以用作传感器来测量应变，温度，和其他参数。作为地震或声纳水听器光学纤维。
11. Summary 总结
Because optical communications can send lots of information at very high speed, it will change our society and make our lives more enjoyable and comfortable. 因为光通信可以以非常高的速度发送大量的信息，它将改变我们的社会，使我们的生活更愉快和舒适。