臺灣博碩士論文加值系統

本論文之目的在研究光固子於雷曼放大光纖中之傳播及在光通訊上之應用。光脈衝在
光纖中傳播，會因色散而使脈衝寬度增長，這限制了訊號傳輸率。利用柯爾效應造成
的自相位調變，當光固子的載波波長在負色散區域時，色散可以被抵消而保持其波形
。當光固子的載波波長接近零色散波長時，其所需功率可以降低。以數值解光固子所
滿足的波動方程，我們得到在無損耗光纖中，接近零色散波長的光固子之近似解。因
光固子在有損耗的光纖中不能保持其波形，需要以雷曼放大抵消損耗。因此，也研究
了如此的光固子於周期性的雙向雷曼放光纖中之傳播，以及光固子波長多工通訊。結
果顯示，接近零色散波長時，光固子因功率變化造成的波形改變和碰撞造成的速度改
變都會減少。在文獻中，雷曼放大光被假設成延著光纖行進都為連續波。我們發現這
不一定成立。事實上，光固子與前向雷曼放大光之交互作用會產生互相位調變。這效
應會使光固子的波形及速度改變。在適當的條件下，其波形可以保持住，但速度則不
行。我們導出因速度變化造成的光固子位移。最後，我們研究在無損耗光纖中的光固
子波長多工通訊系統之雷曼串音，發現除了能量由具短載波波長的光固子轉移到具長
載波波長的光固子外，也增加了兩光固子之頻率漂栘。由數值結果，我們得到在波長
多工系統中，這能量轉栘對訊號傳輸率與傳輸距離之乘積的限制。

CONTENTS
CHINESE ABSTRACT
ENGLISH ABSTRACT
ACKNOWLEDGEMENT
FIGURE LIST
CHAPTER 1 GENERAL INTRODUCTION
1-1 Appilcation of optical soliton to optical communication system
1-2 Nonlinear Schroedinger equation and fundamental soliton solution
1-3 Propagating beam method
CHAPTER 2 APPROXIMATE SOLUTION OF OPTICAL SOLITON IN A LOSSLESS FIBER WITH THIRD-ORDER DISPERSION
2-1 Intrduction
2-2 Wave equation and initial condition
2-3 Numerical results
2-4 Soliton with frequency shift
2-5 Summary
CHAPTER 3 OPTICALSOLITON NEAR ZERO-DISPERSION REGIME IN A RAMEN PUMPES FIBER
3-1 Introduction
3-2 Wave equation and initial condition
3-3 Single soliton propagation
3-4 Two soliton collision
3-5 Summary
CHAPTER 4 INTERACTION OF OPTICAL SOLITONS WITH A FORWARD RAMAN PUMP WAVE
4-1 Introduction
4-2 Wave eqution and initial condition
4-3 Cross-phase modulation between optical soliton and forward pumop wave
4-4 Strong cross-phase modulation
4-5 summary
CHAPTER 5 SOLITON TRANSMISSION WITH PERIODICALLY BIDIRECTIONAL RAMAN PUMPS
5-1 Introduction
5-2 Relative velocity between forsard pump wave and optical soltion
5-3 Wave equation and initial condition
5-4 Solitons propagate in positive relative reciprocal group velocity regime
5-5 Displacement of the soliton caused by velocity change
5-6 Summary
CHAPTER 6 SOLITON COLLISION WITH RAMAN CROSSTALK IN A LOSSLESS FIBER
6-1 Introduction
6-2 Wave equation and initial condition
6-3 raman crosstalk induced by soliton collision
6-4 Limitation caused by depletion in WDM system
6-5 summary
CHAPTER 7 CONCLUSION
7-1 Summary
7-2 Suggestion for future researches
REFERENCES
FIGURES
BIOGRAPHY