提出的一种由掺铒光纤动态光栅和光纤Bragg光栅构成的Fabry-Perot腔。通过建立二能级掺铒光纤动态光栅模型,根据半经典相互作用理论和传输矩阵理论,计算出掺铒光纤动态光栅以及该Fabry-Perot腔的透过率和反射率,并分析动态光栅中相干探测场拉比频率、掺铒光纤长度、光纤Bragg光栅的折射率调制深度以及Fabry-Perot腔的腔长等参数改变时对动态光栅和Fabry-Perot腔反射谱的影响。该Fabry-Perot腔的一个重要性质是其输出光谱可以通过调节探测场的拉比频率、探测场波长等参数进行动态调制。相比于由两个光纤Bragg光栅构成的Fabry-Perot腔,参数可调的系统比参数固定的系统更加灵活,并且能够克服Fabry-Perot腔两端的光纤Bragg光栅不对称的缺点(如不同的Bragg波长、折射率调制深度等),更有利于Fabry-Perot腔的模式选择。该光纤Fabry-Perot腔可以应用于光纤通信的光信号处理或光纤传感领域。

We propose a new type Fabry-Perot cavity based on dynamic grating in Er-doped fiber and fiber Bragg grating. The dynamic grating model is established through two-level system of Er-doped fiber. We calculate the reflection and transmission of the dynamic grating and the Fabry-Perot cavity based on semi-classical interactional theory and transfer matrix method, and analyze the influence of some parameters on reflection spectra of the dynamic grating and Fabry-Perot cavity. An important feature of the proposed Fabry-Perot cavity is that its output spectra can be dynamically tunable by parameters modulation, in which the parameters include Rabi frequency of the coherent probe field in the dynamic grating, the length of the Er-doped fiber, the refractive index modulation depth of the fiber Bragg grating, the cavity length of the Fabry-Perot cavity and so on. Compared with the Fabry-Perot cavity based on two fiber Bragg gratings with fixed parameters, the proposed Fabry-Perot cavity is more flexible, and is more beneficial for mode selection. It can overcome the asymmetrical drawback of the two fiber Bragg gratings in Fabry-Perot cavity (such as different Bragg wavelengths, refractive index modulation depths of Bragg grating). The proposed Fabry-Perot cavity has potential applications in fiber-optic communication and fiber sensors.