Fiber laser sensor for load measurement based on beat frequency demodulation technique

A novel fiber laser load sensor based on beat frequency demodulation technique is presented. When the load is applied on the sensor, the laser cavity will be stretched, which leads to the frequency shift of beat frequency signal. Thus, the load can be obtained by measuring the beat frequency. In the experiment, four different beat frequency signals are studied and compared in the load measurement. The sensitivities are -12.63kHz/kg, -27.80kHz/kg, -41.29kHz/kg, and -53.88kHz/kg, respectively. The paper proposes a cost-efficient scheme for load measurement.