A novel two-mode fiber-optic interferometer employing a liquid-crystal-clad fiber as a modal filter is proposed. The liquid-crystal-clad fiber can guide one of the second-order modes, , and leak out the other and modes. Thus two spatial modes, fundamental mode and second-order mode serve as the two arms of the interferometer to detect an external perturbation. The experimental results obtained when this interferometer was used to sense temperatures ranging from 20 to 100 °C are demonstrated.
© 2004 Optical Society of AmericaFull Article | PDF Article