TITLE:
Optimization of the Tilted Fibre Bragg Gratings for the Fibre Accelerometric Sensor
AUTHORS:
Frantisek Urban
KEYWORDS:
Optical Fibre, Tilted Fibre Bragg Grating, Accelerometric Sensor, Cladding Modes, Reflected Spectrum
JOURNAL NAME:
Journal of Computer and Communications,
Vol.2 No.7,
May
21,
2014
ABSTRACT: The presentation shows the principle and
construction of the fibre optic accelerometric sensor. The sensor element is
based on the use of the tilted fibre Bragg grating (TFBG) that is imprinted to
the bend insensitive single-mode telecommunication grade fibre. The fibre
section with TFBG is then coupled to the evaluation fibre circuit with the cladding-core
mode conversion element that provides the core re-coupling of the optical power
injected by TFBG to the fibre cladding. The cladding-core mode conversion
efficiency is sensitive to the acceleration generated fibre bending. It is
shown that the sensitivity of the device depends on the rate of the main core
reflection versus cladding ghost reflection induced by the grating. The
analysis of the core reflection power coupling on the angle of the grating tilt
and the analysis of the cladding ghost reflection power coupling on the angle
of the grating tilt is presented and the optimal parameters of the tilt and
refractive index modulation are derived. The presentation gives the
experimental results of the TFBG sensor prepared according to the optimization
process.