Deuterium oxide

IA (Molecular weight: 130.1) was purchased from Wako Pure Chemical Corp. (Osaka, Japan). KPS, sodium dihydrogenphosphate, disodium hydrogenphosphate, deuterium oxide, and sodium hydroxide were purchased from Nacalai Tesque Inc. (Kyoto, Japan). All reagents were used without further purification.

Several ϕ50.0 and 0.7 mm-thick SiO₂ (BK7) and IR-grade CaF₂ substrates were purchased from OptoSigma (Tokyo, Japan). All substrates were double-side polished to the optical grade. Drilled on the CaF₂ substrate were ϕ0.7 mm through-holes at specific positions in advance as inlets and outlets for introducing fluidics. Those holes were also used as markers for position alignment. The SiO₂ substrate was cleaned in a piranha solution (H₂SO₄/H₂O₂ = 3:1) before fabrication. In the case of CaF₂ substrate, the UV/O₃ treatment was performed instead of piranha washing. The deposition of SiO₂ and MgF₂ thin films described in Section 3.2.2 and Section 4.3, respectively used source materials that were purchased from Furuuchi Chemical Corp. Sulfuric acid, hydrogen perroxide, acetone, and deuterium oxide of special grade were purchased from Nacalai Tesque (Kyoto, Japan).