在探討二極體雷射和光纖耦合的文獻中，高斯光束常被用來描述雷射光束的分佈，但真實的雷射光束存在像散的問題。為了瞭解真實二極體雷射的光束分佈，我們使用單模光纖干涉儀進行雷射近場能量和相位分佈的量測，利用具奈米孔徑之單模光纖探針，在垂直光傳播軸向的平面上之最大能量位置為中心作水平軸向和垂直軸向移動，測得雷射能量和相位的分佈。其中相位分佈是利用位於雷射前、後兩條單模光纖接收雷射光來產生干涉條紋，當移動光纖探針而另一條參考光纖固定不動時，干涉條紋會因相位差的改變而產生位移，利用干涉條紋的位移來得到雷射光束相對相位分佈情形。實驗中為了增進干涉條紋的穩定度並考慮光纖探針孔徑的問題，針對實驗架構做些微的修正，架構變化依序分為第一型到第四型。
實驗量測結果中，在雷射出光口的平面上，水平軸向和垂直軸向上光束寬度的大小分別為4.11 μm和1.57 μm，而波前曲率半徑在水平軸向和垂直軸向分別為6.59 μm和2.96 μm。光束寬度經由高斯擬合後，於雷射出光口的平面上，光束寬度大小在水平軸向和垂直軸向分別為4.04 μm和0.83 μm，與實驗值分別差了0.07 μm和0.74 μm的大小。光束寬度的實驗量測值與高斯光束擬合曲線有相近的結果，在雷射光束沿z軸傳播方向上，可以看出光束寬度隨著z軸傳播的變化趨勢。在相位分佈的量測上，波前曲率半徑的實驗量測值與高斯光束理論計算值間有差異性存在，在雷射出光口的平面上，波前曲率半徑在水平軸向和垂直軸向利用高斯函數計算後的值分別為11921.5 μm和3.5 μm，較水平軸實驗值大1809倍，垂直軸為實驗值的1.2倍。由於雷射前端的光纖探針其孔徑於實驗中被雷射能量所燒大，造成空間解析度變差，且水平軸向上波前曲率半徑較大及相位分佈的量測能力受限於量測架構，均為造成相位分佈量測有所誤差的原因，進一步雷射出光口相位量測乃在進行中。

In the literatures of investigating the coupling mechanism between laser diodes and fibers, Gaussian beam profile was used to describe the propagation of laser beams. But the real laser diode beams exist astigmatism. In order to understand the distributions of real laser diode beams, we used single-mode fiber interferometer to measure the near-field intensity and phase distributions of laser diodes. The nanometer aperture of taper fiber was used to scan through the horizontal and vertical directions across the maximal intensity point of the planes which were perpendicular to propagation axis to measure the intensity and phase distributions of laser diodes. In the measurement of phase distributions, these two single-mode fibers produced interference fringes through accepting laser beams. When the taper fiber scanned the optical field and the reference fiber kept a fixed distance from a laser diode for a stationary phase, the interference fringes shifted because of the phase difference of laser diodes change. In the measurement, in order to improve the stability of interference fringes and consider the aperture of taper fiber, we altered some experiment frameworks. There were four types of experimental framework.
According to the experiment results of the near-field measurements, the measured beam widths along the horizontal and vertical directions at the laser diode facet were 4.11 μm and 1.57 μm respectively. The measured wavefront radius curvature were 6.59 μm and 2.96 μm in horizontal axis and vertical axis respectively. After Gaussian beam fitting, the beam widths along the horizontal and vertical directions at the laser diode facet were 4.04 μm and 0.83 μm respectively. The difference in beam widths between measured values and Gaussian fitting were 0.07 μm and 0.74 μm. The measured beam widths and the Gaussian beam curve fitting had similar results. We could see that the beam spread tendency in the z-axis for the laser beam which propagated in the z direction. In the phase distribution measurement, the measured wavefront radius curvatures and the theoretically calculated Gaussian beam values had a slight difference. The calculated wavefront radius curvatures at the laser diode facet were 11921.51 μm and 3.48 μm in horizontal axis and vertical axis respectively. They were 1809 times and 1.2 times of the measured values. The aperture of taper fiber was expanded because of the energy of laser beams, which also caused the spatial resolution degeneration. Moreover, the wavefront radius curvature in horizontal direction was biggish so the measurement framework also limited the ability of the phase distribution measurement. The above points were the reasons to cause the error of the phase distribution measurement. Furthermore, the measurement of the laser diode facet is under investigation.

誌謝 i
中文摘要 ii
Abstract iii
目錄 v
圖次 vii
表次 xi
第 一 章 緒 論 1
1.1 研究背景 1
1.2 研究動機 2
1.3 文獻回顧 3
1.4 論文架構 5
第 二 章 理 論 基 礎 6
2.1 單模光纖干涉儀原理 6
2.2 雷射特性 7
2.3 高斯光束傳播理論 9
2.4 傅立葉分析 11
第 三 章 雷 射 近 場 量 測 系 統 14
3.1單模光纖干涉儀 14
3.2雷射近場量測 26
第 四 章 雷 射 近 場 能 量 和 相 位 分 佈 量 測 結 果 30
4.1第一型量測架構的量測結果 30
4.2第二型量測架構的量測結果 43
4.3第三型和第四型量測架構的量測結果 56
第 五 章 結 論 與 未 來 工 作 57
5.1結論 57
5.2未來工作 58
參考文獻 59

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