基于金属孔阵列的聚酰亚胺薄膜太赫兹探测

Terahertz detection of polyimide films based on metal hole arrays

优化设计了多种不同孔径和形状的太赫兹波段的亚波长金属孔阵列结构,结合超薄低折射率的聚酰亚胺(PI)薄膜,探索了太赫兹时域光谱技术对超薄低折射率的探测灵敏性。利用飞秒微加工技术制备了一系列亚波长金属孔阵列结构,利用太赫兹时域光谱技术测试了阵列结构的反射波谱,获得了强烈的反射共振现象。然后在亚波长金属孔阵列结构背面叠加PI薄膜,结果表明太赫兹反射峰出现了显著低频移动现象。利用这一现象,实现了低至10μm的PI薄膜的有效探测,说明亚波长金属孔阵列结构在太赫兹传感领域对检测超薄低折射率薄膜材料有极强敏感性。

Several metal hole array（MHA） structures of different sizes and shapes in THz were designed. The detection sensitivity of the structures with ultra-thin and low refractive index polyimide films, was explored on a THz time-domain system. MHAs with different structures were fabricated with femtosecond micromachining technology, and the THz reflection spectra were measured by the THz time-domain system. By attaching an ultra-thin polyimide （10 μm） film to the MHA, an obvious blue-shift of reflective resonance peak was observed, which indicated a high sensitivity of MHA to low refractive index materials. This characteristic allows us to achieve MHA-based high-sensitive sensor at THz band.