【正文】 明它在現(xiàn)代已大規(guī)模商用化，是目前的主流應用形式。下一章中，首先對Multisim這一應用廣泛的電子仿真軟件進行介紹，并在 Multisim 13中對上面所有電路進行仿真，獲得各個電路中相關元器件的參數(shù)，并給出仿真結果。 關鍵詞 ： LED 光發(fā)射機， LD 光發(fā)射機， LD 組件，自動溫度控制電路，自動功率控制電路 本科畢業(yè)設計論文 2 ABSTRACT Directly modulated optical transmitter is to acplish 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 munication background, superiority of the fiber with respect to the conventional copper wires and future development of optical fiber munication. In the second chapter, it introduces the sources of the optical fiber munication, including lightemitting 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 ponent, indicating that it has a largescale mercialization in modern times and is the mainstream application form. In the next chapter, it detailed designs LED and LD optical transmitter. First, the lightemitting LED circuit was designed. Then it deep studys more plex 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 ponents parameters in various circuit and giving simulation results. Finally, learn how to use Altium Designer software for printed circuit boards, then make printed circuit board for LD ponents and peripheral circuits. KEY WORDS： LD optical transmitter, LD ponents, automatic temperature control circuit, automatic power control circuit 本科畢業(yè)設計論文 3 目 錄 摘 要 .............................................................................................................................. 1 ABSTRACT ................................................................................................................... 2 目錄 ................................................................................................................................ 3 第一章 緒論 ................................................................................................................ 5 光纖通信系統(tǒng) .................................................................................................. 5 光纖通信應用現(xiàn)狀和發(fā)展前景 ...................................................................... 6 本文研究的主要內(nèi)容 ...................................................................................... 6 第二章 光源器件的介紹 .............................................................................................. 7 半導體發(fā)光二極管（ LED） .......................................................................... 7 LED 的結構 ............................................................................................ 8 發(fā)光二極管 (LED)的工作特性 ............................................................. 9 半導體激光器 (LD)........................................................................................ 11 粒子數(shù)反轉(zhuǎn)與光增益 ........................................................................... 11 光學諧振腔與激光器的閾值條件 ....................................................... 13 激光器的結構 ....................................................................................... 15 半導體激光器的特性 .......................................................................... 16 LD 激光器組件 ............................................................................................. 18 第三章 光發(fā)射機的設計 ............................................................................................ 19 LED 光發(fā)射機的設計 ................................................................................... 19 LD 光發(fā)射機的設計 ..................................................................................... 21 LD 組件 ................................................................................................ 21 光源驅(qū)動電路的設計........................................................................... 22 自動溫度控制電路（ ATC）............................................................... 24 自動功率控制電路（ APC） ............................................................... 25 第四章 光發(fā)射機的仿真 ............................................................................................ 27 仿真軟件 NI Multisim的介紹 ..................................................................... 27 LED 光發(fā)射機的仿真 ................................................................................... 27 LD 主驅(qū)動電路的仿真 ................................................................................. 30 LD 自動溫度控制電路 的仿真 ..................................................................... 32 LD 自動功率控制電路的仿真 ..................................................................... 33 本科畢業(yè)設計論文 4 第五章 LD 光發(fā)射機電路的 PCB 板制作 ................................................................ 36 印制電路板制作軟件 Altium Designer 的介紹 .......................................... 36 LD 組件電路 PCB 板的制作 ........................................................................ 36 參考文獻 ...................................................................................................................... 39 致 謝 ............................................................................................................................ 40 畢業(yè)設計小結 .............................................................................................................. 41 本科畢業(yè)設計論文 5 第一章 緒 論 光纖通信系統(tǒng) 通信科學的發(fā)展歷史悠久，從香農(nóng)的信息論到 21 世紀的最新現(xiàn)代通信理論，通信經(jīng)過了長足的發(fā)展。廣義的光