[11p-W631-1~17] 3.11 Photonic structures and phenomena

[11p-W631-8] Large-scale multi-hole tuning of H1 slotted nanocavity for enhancing Q/V in water

〇Eiichi Kuramochi^1,2, Theo Martel², Shota Kita^1,2, Hideaki Taniyama^1,2, Akihiko Shinya^1,2, Masaya Notomi^1,2 (1.NTT-NPC, 2.NTT-BRL)

Keywords:photonic crystal, nanocavity, biosensor

We are exploring the design of single-cell (H1) slotted nanocavity to enhance the Q/V (Q: quality factor, V: mode volume) of the fundamental slot cavity mode in the water. In this study, we increased the number of the holes optimized the position up to 30 and found a new cavity design. A 3D-FDTD simulation assuming of the Si slab index of 3.46 and the water index of 1.31 demonstrated the fundamental slot cavity mode at the cavity wavelength (λ_c) of 1,582 nm with Q of 2.0×10⁵ and V of 0.023 (λ/n)³, where the latter was less than the half of the previous design. The cavity fabricated actually demonstrated experimental Q of 20,000 in Type-I (18 MΩ·cm) ultrapure water purified in our cleanroom. The results strongly encourage the use of the nanocavity for bio-sensing application.