涡旋光束的轨道角动量双缝干涉实验研究

利用计算机全息振幅二元光栅对基模高斯光束进行衍射,实验产生不同阶次拉盖尔-高斯（Laguerre-Gaussian,LG）涡旋光束,用得到的不同阶的LG光束进行双缝干涉实验,根据采集到的干涉条纹扭曲方向及条纹扭曲程度实现涡旋光束轨道角动量的测量,通过调整实验光学系统,分析了LG光束轨道角动量的测量精度.结果表明,基模高斯光束束宽与全息光栅尺寸的合理选择会影响到生成的涡旋光束质量.在确定基模高斯光束束宽的情况下,双缝间距与光束束宽的比例为1：1.5时,双缝对生成的LG光束干涉条纹扭曲效果明显,LG光束轨道角动量测量误差最小.

Study of double-slit interference experiment on the orbital angular momentum of LG beam

Holographical amplitude binary grating on computer is employed to diffract the fundamental-mode Gaussian beam, which gives rise to Laguerre-Gaussian （LG） vortex beam with different orders, LG beam with different orders is used to make two-slit interference test. The measurement of orbital angular momentum of LG beam is made according to twisted direction and extent of selected interference strip. The measurement accuracy of orbit angular momentum of vortex beam is analyzed through ajusting experimental optical system. The result shows that proper choice of the fundamental-mode Gaussian beam width and holographical grating size will interfere the quality of LG beam. Under the assurance of the fundamental-mode Gaussian beam width, the ratio of two-slit interval to Guass light beam width is 1：1.5, the twisted effect of interference strip is dramatic and the mesurement error of orbit angular momentum of LG beam is the least.