隨著科技發展，許多產品都往輕薄短小的方向發展，超穎介面也乘著這波潮流應運而生，其對於光波展現極強的調製能力，加上體積小，與各類光學元件的適配度高，更是衍伸出各種應用，足以取代，甚至是超越傳統的光學元件。
在光學系統中，無可避免的會有像差的問題出現，導致波前扭曲變形，波前感測器能夠有效量測出波前變化，協助使用者判斷如何在後處理時對光學系統中形成的像差進行補正。傳統的Shack Hartmann波前感測器由研磨透鏡陣列組成，當入射光的波前發生改變時，穿過透鏡陣列時形成的一系列的焦點也會隨之位移，透過分析這些光點的位移情形達成波前感測的效果，但研磨透鏡因為其塊材的性質所產生色差現象，讓波前感測器並沒有辦法同時作用於不同波長下，同時也限制了感測器的體積大小。
本篇研究透過幾何相位在設計上的優勢—穿透率的穩地性及節省模擬次數，設計出能夠在可見光波段，多波長同時入射情況下，完成分光、聚焦的超穎透鏡。將其組成超穎透鏡陣列取代傳統的研磨透鏡陣列，提升波前感測器的多工處理能力以及進一步的縮小體積。本研究論文選用氮化鎵奈米柱作為單元組成結構，實現在可見光波段的高穿透率，透過數值模擬完成樣品設計後，以電子束微影製程技術完成樣品的製備，接著使用設計好的光學系統，以不同形貌的波前入射樣品進行檢測，將檢測的結果與預期結果進行比對，驗證此設計的可行性。可以看到量測結果與預期結果的高度吻合，展示其在波前感測上的可行性，以及超穎透鏡在平面光學上的延伸應用。

Traditional wavefront sensors can reconstruct the wavefront through different focusing behaviors, but the chromatic aberration and large size of polished lenses pose certain limitations in use. Compared to traditional polished lenses, metalens offer smaller size and achromatic properties, which gives us an ides of replacing polished lenses with metalens in order to effectively solve limitations mentioned above.
In this study, we design a metalens made of GaN nanopillars, which is capable of splitting and focusing four different wavelengths simultaneously. Through these metalens array, we can easily detect different wavefront of four wavelength. With different focusing behaviors, the wavefront is then reconstructed using methods such as Zernike polynomials.

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