High-power laser induced thermal blooming effects in a closed chamber with three different gases are investigated theoretically and experimentally in this work. In the theoretical treatment, an incompressible gas turb...High-power laser induced thermal blooming effects in a closed chamber with three different gases are investigated theoretically and experimentally in this work. In the theoretical treatment, an incompressible gas turbulent model is adopted.In the numerical simulation the gas refractive index as a function of both the temperature and pressure is taken into consideration. In the experimental study the pump-probe technology is adopted. A high-power 1064-nm fiber laser with maximum output power of 12 k W is used to drive the gas thermal blooming, and a 50-m W high-beam-quality 637-nm laser diode(LD)is used as a probe beam. The influences of the gas thermal blooming in the chamber on the probe beam wavefront and beam quality are analyzed for three different gases of air, nitrogen, and helium, respectively. The results indicate that nitrogen is well suitable for restraining thermal blooming effect for high-power laser. The measured data are in good agreement with the simulated results.展开更多
热晕效应是高能激光大气传输最重要的非线性效应之一。利用激光大气传输四维仿真程序,针对高能固体脉冲激光大气传输的非线性热晕效应,采用常规自适应光学系统与随机并行梯度算法自适应光学系统对其相位补偿进行了数值模拟和分析。结果...热晕效应是高能激光大气传输最重要的非线性效应之一。利用激光大气传输四维仿真程序,针对高能固体脉冲激光大气传输的非线性热晕效应,采用常规自适应光学系统与随机并行梯度算法自适应光学系统对其相位补偿进行了数值模拟和分析。结果表明:当脉冲宽度1 ms,重复频率10 Hz,单脉冲发射功率500 k W时,常规自适应光学系统补偿效果较好;当脉冲发射功率增加或者重复频率增加时,随机并行梯度下降算法自适应光学系统补偿效果较好。展开更多
基金Project supported by the National Natural Science Foundation of China(Grant No.61875208)。
文摘High-power laser induced thermal blooming effects in a closed chamber with three different gases are investigated theoretically and experimentally in this work. In the theoretical treatment, an incompressible gas turbulent model is adopted.In the numerical simulation the gas refractive index as a function of both the temperature and pressure is taken into consideration. In the experimental study the pump-probe technology is adopted. A high-power 1064-nm fiber laser with maximum output power of 12 k W is used to drive the gas thermal blooming, and a 50-m W high-beam-quality 637-nm laser diode(LD)is used as a probe beam. The influences of the gas thermal blooming in the chamber on the probe beam wavefront and beam quality are analyzed for three different gases of air, nitrogen, and helium, respectively. The results indicate that nitrogen is well suitable for restraining thermal blooming effect for high-power laser. The measured data are in good agreement with the simulated results.
文摘热晕效应是高能激光大气传输最重要的非线性效应之一。利用激光大气传输四维仿真程序,针对高能固体脉冲激光大气传输的非线性热晕效应,采用常规自适应光学系统与随机并行梯度算法自适应光学系统对其相位补偿进行了数值模拟和分析。结果表明:当脉冲宽度1 ms,重复频率10 Hz,单脉冲发射功率500 k W时,常规自适应光学系统补偿效果较好;当脉冲发射功率增加或者重复频率增加时,随机并行梯度下降算法自适应光学系统补偿效果较好。
