Research on the gas refractive index sensing based on microfiber double-knot resonator with a parallel structure

In this paper, we propose a method based on microfiber double-knot resonator with a parallel structure to detect the volume content of the hybrid gases of CO and CO2. The primary principle is that the mixed gases with different volume ratios have different refractive indexes (RIs). The transmission spectrum of the microfiber resonator immersing into the hybrid gases with different volume ratios will produce a spectral drift. The volume content...