飞秒激光微加工制备大尺寸无衬底太赫兹线栅偏振器

Fabrication of Large-Scale Free-Standing Terahertz Wire Grid Polarizer by Femtosecond Laser Micro-Machining

基于有限差分时域方法(FDTD),设计了两种具有增强线结构的太赫兹线栅偏振器,用于消除重力和空气扰动对偏振器性能的影响;利用飞秒激光微加工制备了偏振器,通过时域太赫兹光谱测试偏振器的性能,并将其与商用线栅偏振器进行了比较,发现偏振器的透射率与FDTD结果吻合,具有不连续增强线的偏振器的偏振度和消光比优于商用线栅偏振器。

Based on the finite-difference time-domain(FDTD)method,two kinds of terahertz line grid polarizers with enhanced line structures are designed to eliminate the influences of gravity and air disturbance on the performance of polarizers.The polarizers are fabricated by femtosecond laser micro-machining.The performance of polarizers is measured by time-domain terahertz spectroscopy and is compared with that of a commercial line grid polarizer.It is found that the transmittance of the polarizers is consistent with FDTD results.The degree of polarization and extinction ratio of the polarizer with discontinuous enhancement lines are better than that of commercial line grid polarizers.