Fiber optic strain sensing with phase-shifting interferometric techniques

摘要

Abstract: We present the performance of a sensor with an optical fiber strain gauge. The system adopts a phase-shifting technique with an equal phase shifting modulation to determine the strain on the sensor. It is accomplished by applying a triangle-wave-modulated signal to the injection current of a visible laser diode with precision temperature control, and its demodulation technique employs a digital signal processing (DSP) to calculate the phase of strain and a statistic processing to improve the signal-to-noise ratio. The experiments show that the relation between the optical phase difference and the external strain is linear. !8