In virtue of the significance of ultrashort vortex pulses, a mode-locked LG₀₁-mode vortex Ti:sapphire laser is first realized. In the study, an intra-cavity spot-defect spatial filter was used to suppress the TEM₀₀ mode’s oscillation and a semiconductor saturable absorber mirror was used as the mode-locked device. As a result, the mode-locked laser emitted LG₀₁-mode vortex pulses of 186 ps at 804.4 nm with a repetition rate of 78.95 MHz and a maximum average output power of 176 mW. The phase of the LG₀₁ mode was measured by a Mach–Zehnder interferometer and both right- and left-handed helical wavefronts were obtained.

中文翻译：

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基于SESAM的锁模涡流Ti：蓝宝石激光器，使用点缺陷空间滤波器进行腔内模式选择

凭借超短涡旋脉冲的重要性，首先实现了锁模LG ₀₁模涡旋Ti：蓝宝石激光器。在研究中，使用腔内斑点缺陷空间滤波器来抑制TEM ₀₀模式的振荡，并使用半导体可饱和吸收镜作为锁模器件。结果，锁模激光器在804.4 nm处发射186 ps的LG ₀₁模式涡旋脉冲，重复频率为78.95 MHz，最大平均输出功率为176 mW。通过Mach-Zehnder干涉仪测量LG ₀₁模式的相位，并获得右旋和左旋螺旋波前。