In this research, amplitude Fresnel zone plates (FZPs) were fabricated on fused silica glass with femtosecond laser. The focusing characteristics including focal length, diffraction efficiency, geometric concentrator ratio, spot energy uniformity, depth of focus and resolution were studied by simulations and experiments. To optimize the focusing characteristics of FZP, we proposed an optimized machining process, an extended FZP and an fractal FZP. The optimized machining process increased the diffraction efficiency of the amplitude FZP from 6.96% to 8.14%, the extended FZP broke through the limit of minimum line width in processing and improved the resolution, and the fractal FZP increased the focus depth from 4 mm to 10 mm. In addition, we wrote a FZP on the end face of multi mode fiber, the divergent annular beam converged and formed an focus ring at the focal plane. This research will provide broad applications in fiber tweezers, beam coupling and optical communication.

在这项研究中，使用飞秒激光在熔融石英玻璃上制造了振幅菲涅耳波带片（FZP）。通过仿真和实验研究了聚焦特性，包括焦距，衍射效率，几何聚光比，点能量均匀性，聚焦深度和分辨率。为了优化FZP的聚焦特性，我们提出了优化的加工工艺，扩展的FZP和分形FZP。优化的加工过程将振幅FZP的衍射效率从6.96％提高到8.14％，扩展的FZP突破了加工中最小线宽的限制并提高了分辨率，分形FZP将聚焦深度从4 mm增加到了10毫米。此外，我们在多模光纤的端面上编写了FZP，发散的环形光束会聚并在焦平面处形成聚焦环。这项研究将在光纤镊子，光束耦合和光通信中提供广泛的应用。