无衍射光的中心光斑直径相对于高斯光束较小且发散角为零，在自由空间光通信领域具有良好的应用前景。介绍了一种自由空间无衍射光通信模拟实验系统，它通过串口连接上位机，应用微处理器进行信号的调制与解调，采用双头脉冲间隔调制，无衍射光的发生使用圆锥透镜法，在接收端使用PIN光电二极管将光信号转换为电信号，再经过放大电路、整形电路和微处理器的解调，最后通过串口将数据传输给上位机。上位机通过对发送数据与接收数据的对比计算出误码率，进而给出整个系统的传输性能评价。在无衍射光的最大传输距离内，当比特率为9 600 bps时，该系统的误码率优于6×10-5。

The non-diffracting beam has smaller central spot than Gaussian beam and zero divergence angle, therefore it has significant prospect of application in free-space optical communication. A free-space optical communication experimental simulation system based on non-diffracting beam is introduced. The system is connected to the computer by serial port. A microprocessor is used for signal modulation and demodulation by adopting dual header-pulse interval modulation. An axicon is employed to generate non-diffraction beam. In the receiving terminal, a PIN photodiode is used to transfer the optical signal to electrical one. The electrical signal is amplified, shaped and demodulated. The data after demodulation are eventually transferred to the computer by serial port. The error rate is calculated by comparing the sending data and receiving data in the computer. The transmission performance of this system is also evaluated. The error rate is less than 6×10-5 within the maximum transmission distance when the bit rate is 9 600 bps.