[22a-C201-1~10] 3.8 Terahertz technologies (formerly 3.9)

△ [22a-C201-5] Fabrication of stacked sub-wavelength structured silicon using fusion bonding

〇Lisa Toyoshima¹, Kasumi Miyata¹, Kaito Tanaka¹, Koudai Iijima¹, Yuka Goto¹, Yoshinori Shohmitsu², Toshihiro Nakaoka¹, Takehiko Wada² (1.Sophia Univ., 2.ISAS/JAXA)

Keywords:fusion bonding, sub-wavelength structure, interference filter

Refractive index control by sub-wavelength structure (SWS) is widely applied for varieties of optical devices. On the other hand, compared to two-dimensional refractive index control of a surface using lithography, controlling three-dimensional refractive index by stacking still have obstacles. In this presentation, we report multi-layered interference filter fabricated by fusion bonding stacking of SWS layers fabricated on device layer of SOI wafer, controlling refractive index in the vertical direction. The experimental and simulated transmittance matched in the wavelength longer than 51.3μm where there is no influence of diffraction. In addition, we succeeded in stacking SWS layers of effective refractive indexes 1.6 and 2.7 using fusion bonding.