近年來，在同調光通訊系統的蓬勃發展下，已經接近了一個臨界點，也就是該系統的容量或是錯誤發生率大致上都被光的量子效應所侷限住了，而這個量子效應通常被稱為散粒效應(shot noise)，只要是用光做為通訊媒介的系統，大多都無法避免這個限制，於是許多研究學者開始往對雷射激發出來的光進行量子壓縮(quantum squeezing)的研究，而到目前為止，大多數研究都是在光的維度上探討量子壓縮的技術，但在本論文中，主要是探討將此一技術或概念運用在電的維度上進而增加同調光通訊系統接收器的敏銳度的可能性。在本論文中，將會解釋量子壓縮技術的理論，然後將此一技術概念套用在直接調變(IMDD)以及二位元相位偏移調變(BPSK)的數值模擬上，來驗證其是否可運用於同調光纖系統的接收器上，並達到降低錯誤發生率的功效；以及運用兩個新的演算法來嘗試在電的維度上模擬出光學上的量子壓縮技術，以及探討將該組演算法套用到BPSK模擬上是否能降低錯誤發生率的可能性，在本論文中對此組演算法會有進一步的解釋及驗證。

Coherent lightwave communications systems are approaching a limit where the error rates and channel capacities are limited by the quantum properties of light. This is often referred to as the shot-noise limit. If ideal laser light is used in the system, there is no way to avoid this limit. However, a novel idea to improve the receiver sensitivity of the coherent detection system is proposed in this master thesis. This novel idea is fulfilled through some numerical simulations. The theoretical study of quantum squeezing is explained, and the simulation method uses two algorithms to compose. The details of these two algorithms, phase rotation and phase sensitive amplification, will be explained. There are two simulations demonstrated in this master thesis, intensity modulation direct detection (IM-DD) and binary phase shift keying (BPSK). The results for these two simulations are demonstrated after the explanations of both simulations.

中文審定書　　i
致謝　　ii
中文摘要　　iii
Abstract　　iv
Contents　　v

1　Introduction　　1
1.1　Background knowledge　　1
1.2　Motivation and research method　　2
1.3　Structure of this Thesis　　3
References　　5

2　Theory of quantum squeezing　　6
2.1　Heisenberg's uncertainty principle　　6
2.2 Theoretical study of quantum squeezing　　7
References　　10

3　Theoretical study and simulation of IM-DD and BPSK formats　　11
3.1　Introduction 　　11
3.2　Basic theory and scheme of IM-DD 　　11
3.3　Simulation of IM-DD and result 　　12
3.4　Basic theory and scheme of BPSK 　　17
3.5 Simulation of BPSK and result 　　18
3.6 Novel algorithm to adopt squeezed state　　22
3.6.1 Phase rotation 　　23
3.6.2 Phase sensitive amplification 　　29
3.6.3 Combination of two algorithms and BER simulation 　　31
References 　　38

4　Summary　　39

chapter 1
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chapter 2
[1] Derek Abbott, Jeffrey H. Shapiro, Yoshihisa Yamamoto “Fluctuation and Noise in Photonics and Quantum Optics ”, SPIE, Vol5111, 2003.
[2] Raymond A. Serway, Clement J. Moses, Curt A. Moyer “Modern Physics 3rd edition” chapter 5 page 173-178, the Heisenberg Uncertainty principle, 2005.
[3] Richart E. Slusher and Bernard Yurke, “Squeezed Light for Coherent Communications”
[4] Partha Sarathi Gupta, “Squeezing of Radiation in Nonlinear Optical Processes”, SPIE, Vol. 4797, 2003.
[5] H. P. Yuen, “Two photon coherent states of the radiation field”, Phys. Rev. A, Vol.13, p.2226, 1976.

chapter 3
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