Slot-waveguide biochemical sensor

TLDR

We report an experimental demonstration of an integrated biochemical sensor based on a slot‑waveguide microring resonator. The sensor is a Si₃N₄–SiO₂ slot‑waveguide microring resonator operating at 1.3 µm, whose transmission spectrum is measured across ambient refractive indices from 1.33 to 1.42. The resonant wavelength shifts linearly by 212 nm per RIU, enabling detection of refractive index changes as small as 2 × 10⁻⁴ RIU.

Abstract

We report an experimental demonstration of an integrated biochemical sensor based on a slot-waveguide microring resonator. The microresonator is fabricated on a Si3N4-SiO2 platform and operates at a wavelength of 1.3 μm. The transmission spectrum of the sensor is measured with different ambient refractive indices ranging from n=1.33 to 1.42. A linear shift of the resonant wavelength with increasing ambient refractive index of 212 nm/refractive index units (RIU) is observed. The sensor detects a minimal refractive index variation of 2×10−4 RIU.