涡旋光束轨道角动量的十字线检测法

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中图分类号：0436 文献标志码：A doi：10.37188/CO.2024-0209 CSTR：32171.14.CO.2024-0209

Abstract： In this paper， a method for vortex beam OAM detection using crosshair difraction is proposed. The OAM-related main bright spot in the far-field distribution contains most of the energy of the incident beam （50%-84% ）and there is no secondary bright spot that interferes with the detection.In contrast， the energy proportion of the main bright spot in the conventional small-hole difraction method is extremely low， particularly inthe far-field main bright spot above the 7th-order topological charge， which contains less than 1% of the energy of the incident beam. Furthermore，as the topological charge level increases，the secondary bright spot becomes more intrusive. Consequently， crosshair measurements are particularly applicable to the detection of weak vortex beams， which has potentially important implications for the development of longrangefree-spaceoptical communications.

Key words： diffraction; vortex beam; orbital angular momentum; topological charge

1引言

1992年，Allen等人指出涡旋光束携带有轨道角动量（orbital angular momentum，OAM）[1]。（剩余11155字）