Development of the Offset Locking Based Distributed Sensor

摘要

The application of optic fiber in the sensing field is booming in recent years. Based on Brillouin frequency shift linearly related to strain and temperature, various distributed sensors have been developed and commercialized. We used pump and probe lasers to get the counter-propagating Brillouin gain and loss spectrum. Two narrow linewidth diode-pumped Nd-YAG lasers were locked at the Brillouin frequency. In this project, we use two DFB lasers to replace diode-pumped Nd-YAG lasers to reduce the cost of the system. The offset locking technique and an optical delay line have been applied in the system. We also simulated this sensor system considering the DFB lasers' broader linewidth compared with frequency stablized Nd-YAG lasers.