混合光环晶格的实验研究

Experimental study on hybrid optical ring lattices

混合光环晶格是由束腰半径相同、拓扑电荷数分别为整数和分数的两束拉盖尔-高斯(LG,Laguerre-Gaussian)涡旋光束共轴叠加而成。本文理论模拟产生了混合光环晶格,包括混合亮环晶格和混合暗环晶格;基于共轭对称延拓傅里叶计算全息生成了混合光环晶格的全息图,并利用反射式空间光调制器(SLM),光电再现了高质量的混合光环晶格,实验结果与理论模拟一致。研究表明,混合光环晶格可以揭示拓扑电荷数的变化对光环晶格的光束分布影响,对深入理解复合涡旋光束提供了实验依据。

Hybrid optical ring lattices are generated by coaxial superposition of two Laguerre-Gaussian vortex beams with the same waist parameters and different topological charge numbers of integer and fraction respectively. We simulate the hybrid optical ring lattices theoretically, including hybrid optical bright-ring lattice and hybrid optical dark-ring lattice. The holograms of hybrid optical ring lattice are en- coded using Fourier computer-generated holography based on conjugate-symmetric extension. Employing a reflected-type spatial light modulator, we reconstruct the hybrid optical ring lattices by optical experi- ment. Excellent agreement between theoretical and experimental results is achieved. Researches show the influence of topological charge number on the distribution of optical ring lattices, and provide some ex- perimental basis for understanding composite vortex beams.