High sensitivity refractive index sensors with different no-core fiber diameters.

We investigate refractive index (RI) sensors using no-core fibers with diameters of 250 µm, 125 µm, and 62.5 µm. Experiments show that RI sensors with sizes of 62.5 µm and 250 µm are more sensitive than those with a diameter of 125 µm. The maximum RI sensitivity was 4886 nm/RIU. The RI sensor has a high sensitivity, a wide measurement range, and is insensitive to temperature, making it well-suited for a variety of practical applications. [ABSTRACT FROM AUTHOR]