采用多量子阱器件的无线光通信差拍接收方案研究

Research of Heterodyne Reception Optical Wireless Communicatio n Utilizing Photorefractive Multiple Quantum Well Device

研究一种采用光折变多量子阱器件的无线光通信自差拍接收方案。与寻常相干接收方案相比 ,省去了中频跟踪电子系统 ;与量子阱器件零拍方案相比 ,采用中频窄带滤波器 ,提高了接收端机的输出信噪比。理论上研究了自差拍相干接收方案 ,从其物理机制出发 ,结合信噪比分析 ,探讨了影响相干接收方案的主要因素。建立了该方案的实验系统 ,并开展了有意义的实验研究。理论分析及实验结果表明 ,该方案对激光大气传输所引起的诸多不利影响皆有一定的抑制作用 ,因而有可能应用于卫星地面激光通信和地面无线光通信系统。

A novel heterodyne reception of optical wirele ss communication adopting photorefractive multiple quantum well device is discussed. Compared with the conventional heterodyne scheme, it avoids the complicated intermediate-frequency tracking system. Compared with homodyne reception using multiple quantum well device, the noise is suppressed dramatically with the help of electronic intermediate-frequency filter. Consequently, the signal-to-noise ratio is improved. The theoretical expression of self-coherence signal is deduced. And the expression of signal-to-noise ratio is given. The impact on the novel heterodyne reception scheme is also analyzed in detail. An experiment of the scheme is conducted. The result of theoretical calculations and experiment show that the scheme can repress to a certain extent many problems due to laser transmission in the atmosphere. This new scheme can be applied to satellite-ground laser communication and terrestrial optical wireless communication.