WAVELENGTH SHIFT AND SPLIT OF CLADDING MODE RESONANCE IN MICRO-BENDED LONG-PERIOD FIBER GRATING UNDER TORSION

摘要

The spectrum behavior of micro-bended long-period fiber gratings is investigated under torsional load. A resonance wavelength shift proportional to the square of the twist angle has been observed for various cladding modes. The resonance peaks split, reduce their amplitude, and finally disappear with increasing twist rate.