Refractive index sensor based on liquid-filled defect hollow core Bragg fiber for high index sensing

We propose a refractive index (RI) sensor based on a liquid-filled defect hollow core Bragg fiber (DHCBF) for high index sensing, in which a resonant wavelength resulted from the transverse resonant coupling effect between core modes and defect modes is utilized as the characteristic wavelength. The linearity and sensitivity strongly depend on structural parameters of defect layer. Accordingly, we numerically demonstrate a high linearity RI sensor with a high sensitivity of 753nm/RIU in the large range of 1.477 to 1.645, by optimally designing the defect layer in a liquid-filled DHCBF. The sensitivity of 532nm/RIU with slightly higher linearity is still can be achieved even when the cladding material dispersion is included.