本研究以鎖模之鈦藍寶石飛秒雷射在高分子材料中引發雙光子吸收效應以製作波導微結構。雷射光以物鏡聚焦於光阻膜中，藉由短脈衝雷射的高瞬時功率引發雙光子吸收使光阻產生聚合反應，以此機制製作出可傳輸光訊號的波導，實驗中探討多項製程參數與製作成果的關係，並與理論模型相驗證，推導出能使光阻聚合的最低閥值曝光劑量，並以此為依據成功製作出截面結構尺寸為20μm×20μm 的光波導，其在波長532nm 的傳輸損耗為0.79dB/cm。 此外，本研究也嘗試以控制光束入射方向的方式一次構裝波導與微反射面，目前尚無法完成45°之斜面供光連結技術應用，但證實改變光束入射方式可製作出擁有斜面的波導結構，利用模擬和實驗比較，為將來改良製程提供方向。In this thesis, waveguiding micro-structures fabricated using two photon absorption induced polymerization are reported. Mode-locked Ti:sapphire femtosecond laser is focused via an objective lens onto a layer of photoresist which is transparent to the operating wavelength (?=800nm). Parameters such as the output power of the laser and the translation speed of the sample are scanned aiming at resolving the threshold fluence for waveguide fabrication. The experimental results were in close agreement with the theoretical calculation giving a reliable estimation to fabricate waveguides with controllable cross-sections. A polymer waveguide with 20μm×20μm in cross-section was demonstrated,and the propagation loss was measured to be 0.79dB/cm at wavelength of 532nm. To integrate waveguides and micro-mirrors in a single fabrication step, direct write was carried out with tilted incidence. The result shows that waveguides with inclined side-walls can be achieved however exact 45-degree turning mirror was not possible due to the limitation of the refraction angle predicted by Snell’s law. Future areas of directions are discussed to overcome this problem.
