利用衍射模式变换器对太赫兹涡旋光束的轨道角动量模式进行鉴别。

Discrimination of orbital angular momentum modes of the terahertz vortex beam using a diffractive mode transformer.

作者信息

Liu Changming, Wei Xuli, Niu Liting, Wang Kejia, Yang Zhengang, Liu Jinsong

出版信息

Opt Express. 2016 Jun 13;24(12):12534-41. doi: 10.1364/OE.24.012534.

DOI:10.1364/OE.24.012534

Abstract

We present an efficient method to discriminate orbital angular momentum (OAM) of the terahertz (THz) vortex beam using a diffractive mode transformer. The mode transformer performs a log-polar coordinate transformation of the input THz vortex beam, which consists of two 3D-printed diffractive elements. A following lens separates each transformed OAM mode to a different lateral position in its focal plane. This method enables a simultaneous measurement over multiple OAM modes of the THz vortex beam. We experimentally demonstrate the measurement of seven individual OAM modes and two multiplexed OAM modes, which is in good agreement with simulations.

摘要

我们提出了一种利用衍射模式变换器来区分太赫兹（THz）涡旋光束轨道角动量（OAM）的有效方法。该模式变换器对输入的太赫兹涡旋光束进行对数极坐标变换，它由两个3D打印的衍射元件组成。随后的透镜将每个变换后的OAM模式分离到其焦平面上的不同横向位置。这种方法能够对太赫兹涡旋光束的多个OAM模式进行同时测量。我们通过实验演示了对七个单独的OAM模式和两个复用的OAM模式的测量，测量结果与模拟结果高度吻合。