Optimization of the Tilted Fibre Bragg Gratings for the Fibre Accelerometric Sensor

Frantisek Urban

1Dept of Microelectronics, Brno University of Technology, FEEC, Brno, Czech Republic 2Network Group, s.r.o., Brno, Czech Republic.

DOI: 10.4236/jcc.2014.27006                

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.

Keywords

Optical Fibre, Tilted Fibre Bragg Grating, Accelerometric Sensor, Cladding Modes, Reflected Spectrum

Conflicts of Interest

The authors declare no conflicts of interest.

References

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