Femtosecond laser microstructured fibre refractive index sensor with temperature compensation

A femtosecond laser microstructured fibre as a Mach-Zehnder interferometer is proposed and demonstrated, for which the attenuation peak wavelengths of different interference orders are sensitive to the refractive index and temperature of the surrounding medium. Experimental results indicate refractive index sensitivities of -13.235 and -15.294 nm refractive index unit (RIU) (blueshift) and temperature sensitivities of 0.089 and 0.094 nm/°C (redshift) at two interference orders m₁ of 28 and m₂ of 27, respectively.