Fiber laser sensing based on mechanically-induced long-period gratings

采用三种方法在光纤中形成了压力感生长周期光纤光栅（LPFGs）。例如，机械压力、UV固化粘合剂和磁力。虽然LPFG被称为带阻滤波器，但带通滤波器响应是通过包层到芯模转换获得的。将长周期光纤光栅引入稀土中。掺杂光纤激光器谐振腔，实现了光纤激光器的可调谐运转。利用激光输出功率和波长随长周期光纤光栅工作环境的变化，从激光输出特性出发，实现了温度和压力的同时传感。

Pressure-induced long-period fiber gratings(LPFGs) were formed in fibers by three methods, i. e., mechanical pressure, UV-curable adhesive, and magnetic force. Although the LPFG is known as a band-rejection filter, the bandpass filter response was obtained by cladding-to-core modes conversion. By introducing the LPFG into the rare-earth. doped fiber laser resonator, tunable operation of the fiber lasers was attained. By using the change of the laser output power and the wavelength according to the circumstance of LPFG, simultaneous sensing of temperature and pressure was obtained from the laser output characteristics.