本研究架設四波剪切干涉儀以量測氣體折射率，該系統使用Modified shack-hartmann mask(MHM)元件取代先前由透鏡陣列建構之Shack-Hartmann波前感測模組，為量測折射率提供了一個新的選擇。該石英材質之MHM元件係以半導體製程製作，用於使繞射光形成干涉圖形，以便後續解析折射率。相較於使用透鏡陣列之Shack-Hartmann波前感測模組，此MHM元件不因元件尺寸或是透鏡陣列數量影響取像解析度，且此系統可適用之頻寬範圍較大。本系統是透過分析繞射圖之傅立葉一階干涉點圖再運用反傅立葉轉換回推入射光波前，計算出待測氣體之入射光波前與參考波前之偏轉角，再使用波前偏轉角計算待測氣體折射率。本論文研究MHM之製程技術，深入分析元件品質，並架設於四波剪切干涉系統驗證其效能。;A quadri-wave shearing interferometer is established in this study to measure the refractive index of gas. In this system, a complementary metal-oxide-semiconductor (COMS) sensor and a modified Shack-Hartmann mask (MHM) form a module to replace the Shack-Hartmann wavefront sensor using the lens array in the former system. Thus, this study offers a new option for measuring the refractive index of gas. Meanwhile, the MHM device made is fabricated via semiconductor processes. For generating diffraction patterns on the sensing plane. Compared to the Shack-Hartmann wavefront sensor with the lens array, this approach is not affected by the size nor the number of lenslets in the array, thereby improving the resolution of the captured image. Additionally, the system is applicable over a wider bandwidth. The refractive index of gas is measured via the following procedures. The Fourier transform of the captured image formed by the diffractive beams is counted, and then the first-order spots are obtained. Along with the analyses of the first-order spots, the refractive index of the gas can be derived via wave optics. This thesis studies on the fabrication techniques of MHM and the quality of the fabricated sample. The MHM sample has been integrated in a quadri-wave interferometer to verify its performance.
