在高階諧波產生研究中，相位匹配佔有很重要的地位。實現相位匹配需要對實驗條件進行精確的測量與控制，特別是測量由超短雷射脈衝所產生的電漿密度。本論文聚焦在發展頻域干涉技術來測量毛細管光波導內的電漿密度。基於此技術，我們成功診斷了高階諧波產生過程中所生成的瞬態電漿。這些結果有助於實現高階諧波產生的相位匹配，進而提升短波長輸出的效率。;In high-harmonic generation research, phase matching plays a crucial role. Achieving phase matching requires precise characterization and careful control of experimental con- ditions, particularly in measuring the plasma density produced by ultrashort laser pulses. This thesis focuses on the development of the frequency-domain interferometry for the measurement of the plasma density in a capillary waveguide. Based on this technique, we successfully diagnose the transient state of the plasma generated in the high-harmonic generation process. These results are beneficial for achieving phase matching of higher-harmonic generation, leading to efficient output at shorter wavelengths.
