Wang Zhuoyi, Lu Xingyuan, Hu Zhiquan, Gao Jianbo, Zhang Hao, Zhu Junan, Lu Xiaotan, Hang Yiyi, Cai Yangjian, Zhao Chengliang
Opt Lett. 2024 Dec 15;49(24):7250-7253. doi: 10.1364/OL.542414.
The orbital angular momentum (OAM) of beams provides an additional degree of freedom and has been applied in various scientific and technological fields. Accurate and quantitative measurement of intensity distributions across different OAM modes, referred to as the OAM spectrum of a beam, is crucial. Here, we propose a straightforward and efficient experimental setup for measuring the OAM spectrum of a randomly fluctuating beam. By employing a modal decomposition analyzer, a randomly fluctuating light field can be decomposed into an incoherent superposition of a series of modes, followed by a coordinate transformation to calculate the OAM spectrum. This method is suitable for measuring the OAM spectrum of partially coherent beams and superposition of vortex beams. The experimental results are in good agreement with the theoretical predictions. Precise measurement of the OAM spectrum is critical for various applications in optical communications, quantum optics, and digital imaging.
光束的轨道角动量（OAM）提供了一个额外的自由度，并已应用于各种科学和技术领域。准确且定量地测量不同OAM模式下的强度分布，即光束的OAM光谱，至关重要。在此，我们提出一种简单高效的实验装置来测量随机波动光束的OAM光谱。通过使用模态分解分析仪，一个随机波动的光场可以被分解为一系列模式的非相干叠加，然后通过坐标变换来计算OAM光谱。该方法适用于测量部分相干光束和涡旋光束叠加的OAM光谱。实验结果与理论预测吻合良好。精确测量OAM光谱对于光通信、量子光学和数字成像中的各种应用至关重要。
