光纤通信发射机本科毕业论文 西北工业大学

本科毕业设计论文 PAGE 41

摘 要 直接调制光发射机能完成对电信号的处理，其功能是把电脉冲信号变成光脉冲信号。本文先介绍了光纤通信的发展背景，光纤相对于传统铜导线的优越性，以及光纤通信未来的发展。在第二章中对光纤通信中的光源进行了介绍，其中包括LED发光二极管与LD半导体激光器，详细说明了结构、发光机理、P-I特性、光谱特性、调制特性等工作特性。简单介绍LD组件，并说明它在现代已大规模商用化，是目前的主流应用形式。在后一章中对LED和LD光发射机进行详细设计，首先设计了LED光发射电路，然后深入研究更为复杂的LD激光器调制电路，在对其进行了简单介绍后，说明了自动温度控制电路和自动功率控制电路在LD调制电路中的重要性，然后再对这两种电路进行了设计。下一章中，首先对Multisim这一应用广泛的电子仿真软件进行介绍，并在Multisim 13中对上面所有电路进行仿真，获得各个电路中相关元器件的参数，并给出仿真结果。最后，再学习Altium Designer印制电路板软件的使用，并对LD组件及外围电路进行印制电路板的制作。

关键词：LED光发射机，LD光发射机，LD组件，自动温度控制电路，自动功率控制电路

ABSTRACT Directly modulated optical transmitter is to accomplish the processing of the electrical signal, and its function is to transform the electrical pulse signals into the optical pulse signal. This paper first describes the development of optical fiber communication background, superiority of the fiber with respect to the conventional copper wires and future development of optical fiber communication. In the second chapter, it introduces the sources of the optical fiber communication, including light-emitting diodes(LED) and laser diode(LD). It details the operating characteristics as the structure and luminescence mechanism, PI characteristics, spectral characteristics and modulation characteristics. Then this article briefly introduces the LD component, indicating that it has a large-scale commercialization in modern times and is the mainstream application form. In the next chapter, it detailed designs LED and LD optical transmitter. First, the light-emitting LED circuit was designed. Then it deep studys more complex laser modulation circuit. After a brief introduction, it introduces the importance of automatic temperature control circuit and the automatic power control circuit of the LD modulation circuit. Then it designs these two circuits. In the next chapter, it firstly introduces the application of a wide range of electronic Multisim simulation software, then simulates all the circuit in Multisim 13,accessing to related components paramet