雙光子聚合積層製造設計與實作

Abstract

本論文介紹利用光阻SU-8為試驗材料，透過製作立體結構或平面結構，了解雙光子固化平台實務問題，及利用雷射掃描光固化加速成型時間之可行性。 整體平台分為光路系統與顯微鏡系統。光路系統以波長800 nm之鈦藍寶石飛秒雷射為光源，搭配二分之一波片和偏振片為控制功率，脈衝壓縮器讓每個脈衝保持約95飛秒，聲光調變器控制開關。顯微鏡系統以倒立式顯微鏡為本體，搭配振鏡作二維掃描，透過100X物鏡聚焦於光阻上，Z軸平台達到三維結構，另外搭配一組共軛焦系統確保對焦。 此雙光子聚合平台可在光阻上對圖形的寫入，藉由控制雷射功率與寫入速度可得到不同的解析度(線寬)，合適的光劑量可剛好越過固化門檻值，並且可使解析度小於繞射極限。本論文所達到的最佳解析度(最小線寬)為190 nm。

This thesis introduces the practical issue of two-photon polymerization platform via utilization of the photoresist to fabricate two-dimensional or three-dimensional structures. The feasibility of accelerated polymerization by using laser-scanning system is discussed. The whole system is divided into the optical and microscopy system. Titanium sapphire femtosecond laser, centered at 800 nm, is used as the light source in the optical system. A half wave plate and polarizer are used to control the power. The pulse duration is compressed to be ~ 95 femtosecond in front of the sample. The switch of the light source is achieved by an acousto-optic modulator. The microscopy system includes an inverted microscope, incorporated with a galvanometer mirrors for two-dimensional laser scanning. The depth dimension of the structure is controlled by a motorized stage and monitored with a confocal system. By controlling the laser power and writing speed, this two-photon polymerization platform is capable of writing the structures on the sample (photoresist on substrate) with different resolution (linewidth). The resolution of the polymerized structure can be achieved by suitable light dosage, which just exceeds the threshold of polymerization. The optimal resolution (minimum linewidth) achieved in this thesis is 190 nm.