液晶元件在深藍光到紫外光波段光穩定性之研究

Abstract

今日，液晶作為光學元件已被廣泛用於波長低於450 nm的許多光學器件中。然而大多數有機材料對波長低於400 nm以下的高功率輻射是很敏感的。因此，在這項研究中，將著重於液晶光學元件在被深藍色（405 nm）到紫外光（365 nm）照射後的性能表現。因為液晶在短波長的能量積累的穩定性對工程師在光學元件設計上是一項很重要的評估指標。所以本實驗建構了基於高強度氣體放電光源的高功率短波長光源系統來評估選定的液晶光學材料。此研究選擇了主要吸收波長低於350 nm的且在雙折射率差異較大的兩種液晶混合物來進行研究。一般認為，紫外光的吸收是造成液晶材料降解的主要原因。 在未知混合物組成的情況下，本研究測試了兩種液晶材料的電光學性質變化,來做為在不同波長應用下的一個材料選擇的標準。

Liquid crystals have been widely used in many optical devices for wavelength beyond 450 nm. However, most organic materials are sensitive with high power irradiation under 400 nm. In this study, the experiment focused on the performance of LC optical elements from deep blue (405 nm) to UV (365 nm) irradiation. As a result, the LC stability and the tolerance to the energy accumulation at the shorter wavelength region are significant evaluation for engineers. The high power short wavelength light system based on High-intensity discharge (HID) light source was constructed to evaluate the LC devices. The LC mixtures with main absorption lower than 350 nm were selected for this study. In general, it is believed that the UV absorption is the major cause of the material degradation. Without knowing the mixture compositions, this is one criterion for material selection besides their electro-optical properties under different wavelength region.