Brunet Charles, Vaity Pravin, Messaddeq Younès, LaRochelle Sophie, Rusch Leslie A
Opt Express. 2014 Oct 20;22(21):26117-27. doi: 10.1364/OE.22.026117.
We present an optical fiber supporting 36 information bearing orbital angular momentum (OAM) states spanning 9 OAM orders. We introduce design techniques to maximize the number of OAM modes supported in the fiber; while avoiding LP mode excitation. We fabricate such a fiber with an air core and an annular index profile using the MCVD process. We introduce a new technique for shaping OAM beams in free-space to obtain better coupling efficiency with fiber with annular index profiles. We excite 9 orders of OAM in the fiber, using interferometry to verify the OAM state on exiting the fiber. Using polarization multiplexing and both signs for the topological charge, we confirm support of 36 states, exploiting to our knowledge the highest number of OAM modes ever transmitted in optical fiber.
我们展示了一种支持36个携带信息的轨道角动量（OAM）状态的光纤，这些状态跨越9个OAM阶数。我们介绍了设计技术，以最大化光纤中支持的OAM模式数量，同时避免激发LP模式。我们使用MCVD工艺制造了一种具有空气芯和环形折射率分布的光纤。我们引入了一种在自由空间中整形OAM光束的新技术，以获得与具有环形折射率分布的光纤更好的耦合效率。我们在光纤中激发9阶OAM，使用干涉测量法来验证光纤输出端的OAM状态。通过偏振复用和拓扑电荷的正负两种符号，我们确认了对36种状态的支持，据我们所知，这是光纤中传输的OAM模式数量最多的情况。
