[16p-A202-1~14] 3.8 Terahertz technologies (formerly 3.9)

[16p-A202-10] Incident angle dependence of terahertz bandpass filter using Babinet’s complementary double metal mesh structure

〇(B)Koudai Iijima¹, Kasumi Miyata¹, Lisa Toyoshima¹, Kaito Tanaka¹, Koh Ohnishi², Yoshinori Shohmitsu³, Toshihiro Nakaoka¹, Takehiko Wada² (1.Sophia Univ., 2.ISAS/JAXA, 3.QUP/KEK)

Keywords:bandpass filter, metal mesh, sub-wavelength structure

Observation of narrow emission lines in the mid-infrared/terahertz region(1THz-10THz) is crucial in infrared astronomy. A metal mesh filter has been conventionally used as the bandpass filter to extract the lines in the region. However, a metal mesh filter is composed of a thin metal film, which makes it less robust to strong mechanical vibrations. We have proposed a robust bandpass filter with a Babinet complementary metal mesh structure and have evaluated its transmission characteristics. In wide-field observations, which are important in astronomy, there is generally a signal from light incident oblique to the filter. In this study, we compare measured and simulated reflection spectra for oblique incidence of light to our filter.