Phase noise reduction by using dual-frequency laser in coherent detection
Phase noise reduction by using dual-frequency laser in coherent detection
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DOI：
10.1016/j.optlastec.2016.01.005
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发表时间：
2016-06
影响因子：
5
通讯作者：
Zheng Zheng-Zheng;Zhao Changming;Z. Haiyang;Yang Suhui;Zhang Dehua;Yang Hongzhi;Li Jiawei
中科院分区：
文献类型：
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作者：
Zheng Zheng-Zheng;Zhao Changming;Z. Haiyang;Yang Suhui;Zhang Dehua;Yang Hongzhi;Li Jiawei
双频激光雷达(DFLR)采用两个相干频率分量的激光作为发射波。该方法基于光学载波射频(RF)信号的使用，该信号是两个分量之间的频差。由于这两个光波通常受到相同的一阶相位噪声的影响，预计合成波比单频波具有更强的抗大气湍流能力。据我们所知，本文提出的模型是第一个详细说明双频激光在抵抗大气湍流方面比单频激光更具优势的模型。通过实验比较了单频和双频激光雷达在大气湍流条件下的性能。实验结果表明，随着大气湍流强度的增加，常规单频相干激光雷达差拍信号的信噪比降低，中心频率稳定度变差。而对于DFLR，信噪比和CFS几乎不受大气湍流的影响，与理论模型吻合较好。
Dual-frequency laser radar (DFLR) uses laser with two coherent frequency components as transmitting wave. The method is based on the use of an optically-carried radio frequency (RF) signal, which is the frequency difference between the two components. Due to the two optical waves are generally subject to the same first order phase noise, the synthesis wave is predicted to have a stronger resistance to atmospheric turbulence than the single-frequency wave. To the best of our knowledge, the model proposed in this paper is the first model that detailedly illustrates that the dual-frequency laser has an advantage over the single frequency laser in atmospheric turbulence resistance. Experiments are carried out to compare the performances of single and dual frequency lidars under atmospheric turbulence. The experimental results show that, with the increase of atmospheric turbulence intensity, the signal to noise ratio (SNR) of beat signal decreases and its central frequency stability (CFS) becomes worse in conventional single frequency coherent laser radar (SFCLR). While for the DFLR, the SNR and CFS are almost unaffected by atmospheric turbulence, which are in good agreement with the theoretical model.