基于高效轨道角动量态分离方法的复用系统方案研究

轨道角动量（OAM,orbital angular momentum）态可载荷信息,单个OAM态具有无穷大容量且不同OAM态间相互正交.基于OAM态复用的通信系统成为光通信和量子光学领域的研究热点之一.将高效OAM态分离方法应用于OAM态复用系统中,给出一种高效的OAM态通信复用方案.由于这种OAM态分离方法的特点,新方案可从OAM叠加态中同时解调出复用系统中不同轨道角动量态的载体信息,有效节省了复用系统接收端的解调设备,降低了OAM态复用系统的实现成本.数值仿真结果表明当系统信噪比大于23 dB时,系统误码率可以降至于10-4以下,本方案是一可行的OAM态复用方案.

An Orbital-angular-momentum-multiplexed Free-space Optical Communications Based on Efficient OAM States Separation Method

Recently, the free space optical communication system based on orbital angular momentum （OAM） states multiplexing has become one of the hot topics in optical communications and quantum op- tics, because OAM states are new dimensional information carriers. An efficient orbital-angular-momen- tum-multiplexed free-space optical communication scheme is proposed, where the efficient orbital angular momentum states separation method is adopted. With this OAM separation method, different orbital angu- lar momentum states can be obtained simultaneously from the superposition OAM state beam, which greatly saves time and the expensive devices for demodulating the information from the information-carry- ing OAM states. Numerical simulation results show that the proposed scheme can reduce time and the number of the devices at the receiver for the information retrieving. The bit error rate of the system can be less than 10 4 when the signal-to-noise ratio of the system is greater than 23 dB. Therefore, this OAM- multiplexed free-space optical communications scheme is proved to be feasible.