用于光束周期性调制补偿的相位载波技术研究

Study on Phase Carrier Technology to Compensate for the Spatial Periodic Modulation of Beam

针对影响高功率激光系统输出性能的空间周期性调制,提出并分析讨论了一种新的基于相位载波灵活补偿控制的方法。首先,理论分析了本文方法对空间周期性调制的空间频率的控制,通过改变相位载波的幅度调节空间频率的强度,并且对于振幅型周期性调制,相位载波的周期可以改变空间频率强度极大值的位置。然后,进行了相位载波对振幅型周期性调制的空间频率影响的实验,实验结果和数值模拟验证了该方法的可行性,并对加载相位载波前后的输出近场图及对应的一维平均功率谱密度曲线进行了对比,加载相位载波后,空间频率的峰值下降了一个量级,并降低到了本底值附近。该方法为高功率激光系统中敏感的空间周期性调制的补偿和控制提供了一个新的思路。

For the spatial periodic modulation that affects the output performance of high power laser systems, a novel method of compensating and controlling the spatial periodic modulation based on phase carrier is proposed and analyzed. First, the theoretical analysis shows that this method is able to control the spatial frequency of the spatial periodic modulation. The intensity of the spatial frequency is modulated by changing the magnitude of the phase carrier, and for the amplitude-type spatial periodic modulation, the period of the phase carrier can change the position of the maximum intensity of the spatial frequency. Then, the experiment on the effect of phase carrier on the amplitude-type spatial periodic modulation is carried out. The feasibility of the method is verified by experimental results and numerical simulations. The output near-field beam and the corresponding one-dimensional average power spectral density curve before and after the phase carrier modulation are compared. It is found that the peak value of the spatial frequency drops by an order of magnitude and decreases to near the background value after phase carrier modulation in the experiment. This method provides a new way to compensate and control the sensitive spatial periodic modulation in high power laser systems.