The simulation and experimental results show that the fiber laser at both ends of the fixed way has a greater influence on the natural frequency of the fiber laser. The metal diaphragm hard fixed way of practical constraints can be considered in the middle state of the clamped and simply supported beam model boundaries, which is closer to the simply supported condition. At low frequencies below 1 kHz, the bending vibration response of the fiber laser is highly related to the first-order natural frequency. In a certain range, the first-order natural frequency of bending vibration of fiber laser increases as prestress increases, which also increases the resonant peak frequency of hydrophone acoustic response. Moreover, hydrophone acoustic response changes dramatically near the resonant peak. Subsequently, the constraint boundary of the fiber beam model can be reset for different design structures. Combined with finite element simulation and experiment, the influence of different fixing modes and packaging structures on the bending vibration of the fiber laser can be further studied.

In the beam model, the variation of the natural frequency of the fiber laser with prestress is consistent with the actual situation. However, the numerical solution of the natural frequency of the fiber beam model is larger than the actual situation under simply and fixed supported boundaries. This is because the small axial displacement is usually ignored in the transverse vibration analysis of the actual beam model. However, the natural frequency of the fiber laser is inevitably affected by the Poisson effect; it decreases the natural frequency. Additionally, the optical fiber beam model of simply and fixed supported on both ends of the constraint conditions and actual packaging are slightly different. Furthermore, packaging materials and the installation of combined components affect the vibration characteristics of fiber lasers. Considering the concrete structure finite element model, the corresponding natural frequency and vibration fluid column experiments have a good match. Therefore, the theoretical model can be refined according to the fixed mode and structure of the fiber laser, combined with the characteristics of the fiber laser to obtain a corresponding numerical solution, which is consistent with the actual solution.