Efficient fabrication of high-quality quartz pendulous via femtosecond laser bessel beams writing-enhanced wet etching

The performance of quartz accelerometers heavily relies on the high-quality fabrication of their key component, the quartz pendulous, which remains a significant challenge using conventional techniques. Here, we propose a femtosecond laser Bessel beam writing-enhanced wet etching method to significantly improve the fabrication efficiency and quality of quartz pendulous. Through orthogonal experiments, we analyze the effects of pulse spacing, single-pulse energy, defocusing distance, and etching time on cutting cross-section roughness and edge residual stress. Using optimized parameters, we achieve high-quality quartz pendulous with an average cross-section roughness of 521 nm, maximum residual stress of 0.496 MPa, and a taper angle of 0.012°. Raman spectroscopy reveals the mechanism of silica glass modification under high-energy laser ablation, forming microcavities along the laser propagation direction. Importantly, the roughness and etching rate are found to be independent of laser polarization. These results demonstrate the effectiveness of the proposed method for high-precision machining of quartz pendulous and other complex glass structures, offering a reliable approach for advanced quartz device fabrication.