精微銑削加工陶瓷粉末高分子複合材料應用於太赫茲光學元件之米氏共振特性研究

Abstract

因應6G通訊的到來及無人自駕車的應用需求，科學家們致力於高頻元件的研究，不管是調變器或是濾波器，在未來皆扮演舉足輕重的地位。然而普遍的調變器或是濾波器皆為金屬材料，有損耗極大的硬傷，因此本研究嘗試使用陶瓷材料ZrSiO4粉末與高分子複合材料PMMA粉末實現擁有高品質因子的共振結構。研究中嘗試使用多種比例進行均勻混合，將混合好的粉末以高溫高壓方式製作成圓形柱狀試片，先由CNC車床將柱狀試片切成直徑約32 mm、厚度約為1.2 mm的圓形薄片進行XRD量測分析樣品結晶狀況及晶體結構，再使用THz-TDS量測樣品折射率。接著將樣品實際量測出結果代入COMSOL Multiphysics®內波光學模組進行模擬。結果顯示，在0.20 THz到0.32 THz頻率之間，並且折射率約為1.8時寬度約為500 µm、深度約為1500 µm的連續中空溝槽結構，會產生共振的現象，之後將模擬出的結果，在3D建模繪圖上建模，轉檔後透過五軸CNC在圓形試片上加工出連續的中空溝槽結構。本實驗採用加工完正面後再翻面加工背面的方式，並透過3D列印的夾冶具協助定位，以此達到正反兩面銑削後之結構能精準的對齊。加工完成後，以雷射共軛焦顯微鏡量測樣品表面粗糙度及使用光學顯微鏡量測實際尺寸與設定之尺寸誤差。最後再進行THz-TDS量測結構共振現象，結果顯示在0.26 THz有共振特徵峰，與模擬出的結果特徵峰相同。本實驗證明有能力根據模擬結果，設計出對應結構，減少該波段的穿透率，未來在光子學、感測及通訊等領域中，可以根據該元件使用的波段及應用場合，選擇合適的尺寸，透過CNC的加工，完成多樣化的元件。In response to the advent of 6G communication and the application needs of autonomous driving, scientists are dedicated to researching high-frequency components, whether modulators or filters, which will play a crucial role in the future. However, common modulators or filters are typically made of metallic materials, which suffer from significant losses. Therefore, this study attempts to use ceramic material ZrSiO4 powder and polymer composite material PMMA powder to achieve a resonant structure with a high-quality factor. The study attempts to mix various proportionsuniformly and make circular cylindrical specimens from the mixed powders using high temperature and high pressure. First, the cylindrical specimens are cut into circular thin slices with a diameter of about 32 mm and a thickness of about 1.2 mm using a CNC lathe for XRD measurement to analyze the sample's crystallinity and crystal structure. Then, THz-TDS is used to measure the refractive index of the samples. Subsequently, the measured results are input into the COMSOL Multiphysics® wave optics module for simulation. The results show that at frequencies between 0.20 THz and 0.32 THz, and with a refractive index of about 1.8, a continuous hollow groove structure with a width of approximately 500 µm and a depth of approximately 1500 µm produces a resonant phenomenon. The simulated results are then used to create a model in 3D modeling software, which is converted and processed on the circular specimens using a five-axis CNC to create continuous hollow groove structures. The experiment adopts a method of processing the front side first and then the back side, and uses 3D-printed jigs for positioning to ensure that the structures on both sides are accurately aligned after milling. After processing, a laser confocal microscope is used to measure the surface roughness of the samples, and an optical microscope is used to measure the actual dimensions and the dimensional errors from the set values. Finally, THz-TDS is used to measure the resonant phenomenon of the structure. The results show a resonant peak at 0.26 THz, which matches the simulated result. This experiment proves the ability to design corresponding structures based on simulation results, reducing the transmittance in that band. In the future, in fields such as photonics, sensing, and communication, appropriate sizes can be selected according to the band and application scenario of the component, and diverse components can be completed through CNC processing.