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介绍了一种基于单纵模分布布拉格反射(DBR)光纤激光器的新型压力传感器。该传感器基于拍频检测原理,其解调方法与传统光波长解调相比成本低且易实现。激光器谐振腔的增益光纤在应力作用下感生双折射从而导致单纵模激光器原本简并的正交偏振模式分离,互相差拍,产生1 GHz左右的拍频。对这种新型传感器进行了理论分析和实验论证,通过对0～1.2 N范围内压力进行传感检测,测得拍频为800～1200 MHz,曲线拟合度达到99.76%。结果表明,该压力传感器不仅延续了光纤光栅传感器高灵敏度等优点。还可以看作是在原有光纤Bragg光栅传感技术的升级,以分布布拉格反射(DBR)代替光纤光栅作为传感基元,将无源传感升级为有源传感,以提高信噪比和传输距离。
A new type of pressure sensor based on single longitudinal mode distributed Bragg reflection (DBR) fiber laser is introduced. The sensor is based on the principle of beat detection and its demodulation method is less costly and easier to implement than traditional optical wavelength demodulation. The gain fiber of the laser resonator induces birefringence under the stress, resulting in the original degenerate orthogonal polarization mode of the single longitudinal mode laser being separated and patting each other, resulting in a beat frequency of about 1 GHz. The theoretical analysis and experimental demonstration of this new sensor are carried out. By measuring the pressure in the range of 0 ~ 1.2 N, the beat frequency is measured at 800 ~ 1200 MHz and the curve fitting degree reaches 99.76%. The results show that the pressure sensor not only continues the advantages of high sensitivity of the FBG sensor. It can also be seen as an upgrade of the original fiber Bragg grating sensing technology, with distributed Bragg reflector (DBR) instead of fiber grating as sensing element, and passive sensing to active sensing to improve signal-to-noise ratio and Transmission distance.