作為一個完整的脈衝量測法，修正場自相關干涉量測法(modified interferometric field autocorrelation, MIFA)尚具有以下優點：可以量測很微弱的脈衝訊號；架構簡單且只要單點光偵測器(point detector)；不需要費時的迭代演算法等。而考慮到實際量測必有誤差的狀況，一個量測法是否能夠在雜訊存在的狀況下仍能量測準確也是必須探討的議題。頻率解析光閘法(frequency-resolved optical-gating, FROG)和頻域相位干涉直接重建電場法(spectral phase interferometry for direct electric-field reconstruction, SPIDER)亦有人做過相關研究。然而過往使用修正場自相關干涉量測法時皆是解析修正場自相關(modified field autocorrelation)函數之絕對值與實部從而解析回頻譜相位(spectral phase)。其中，我們可以從理論預測：解析修正場自相關函數之絕對值時會出現較大數量級的誤差，且會出現修正場自相關函數之虛部與頻譜相位無法確定正負的含糊狀況(sign ambiguity)。本論文創新的非對稱分光修正場自相關干涉量測法(Unbalanced Power Splitting MIFA, UPS-MIFA)透過直接解析修正場自相關函數之實部與虛部，可以解決舊方法的各種問題，從而在雜訊相同條件下得到更小量測誤差。

Modified interferometric field autocorrelation (MIFA) can completely retrieve ultrafast pulse and only need simple device such as point detector and do not need iterative algorithm, and we are interested in its robustness against noise contamination. Frequency-resolved optical-gating (FROG) and spectral phase interferometry for direct electric-field reconstruction (SPIDER) has some similar research too. We come up with a new unbalanced power splitting MIFA (UPS-MIFA) to solve traditional MIFA problems such as sign ambiguity and theoretically larger error by retrieving spectral phase by retrieving real part and imaginary part of modified field autocorrelation instead of its real part and absolute value, and has less error at the presence of the same noise.

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