A novel distributed feedback fiber laser accelerometer based on silicon rubber is developed. The unique mechanism
employed for the accelerometer ensures uniform strain distribution on the fiber laser's Bragg element. A mathematical
model of single-degree-of-freedom system is established, giving the expression of the sensitivity and resonant frequency
of the accelerometer. A multiple-degree-of-freedom simulation with finite element method is also conducted, giving a
more precise prediction of accelerometer's characteristic. Several accelerometers of this type are constructed and tested.
The wavelength shift signal is demodulated using phase generated carrier technique. The experimental result shows they
have a sensitivity of 72 pm/G and a resonant frequency of 415Hz, which agree well with the simulation results. The
minimum detectable signal of the whole sensing system is about 1.5μg. The accelerometer's structure is simple and the
components employed are all commercially available, indicating a great potential in practical use.
A new fiber Bragg grating (FBG) based accelerometer is developed for monitoring seismic activities induced by moving
vehicles. A theoretical model of the sensor is established, and analytical formulas of describing the sensitivity and
resonant frequency are provided. Sensors of this type are fabricated and tested. The experimental results show that they
have a sensitivity of 162.8 pm/G and a resonant frequency of 242.9Hz. The minimum detectable signal of the whole
sensing system is about 12.1 &mgr;g. A field test is carried out to find out that for tracked vehicles' monitoring, a single sensor
has a detection range of about 300 meters, indicating a promising future in practical use.