Guo Jiangtao, Wang Jiangfeng, Pan Xue, Lu Xinghua, Xia Gang, Wang Xiaoqin, Zhang Simin, Fan Wei, Li Xuechun
Appl Opt. 2019 Feb 10;58(5):1261-1270. doi: 10.1364/AO.58.001261.
In order to suppress the frequency modulation to amplitude modulation (FM-to-AM) conversion induced by a Nd:glass regenerative laser amplifier, a birefringent quartz crystal was designed by theoretical simulation and inserted into the regenerative amplifier. A broadband Nd:glass regenerative laser amplifier with a flattop region of ∼3.7 in the gain spectrum was developed. An all-fiber front-end system was used to generate a 2 ns shaped pulse with a spectral width of ∼0.5 , which was broadened by a two-stage phase modulator. Then, the laser pulse was amplified by a spectral-broadened regenerative amplifier. The amplified output temporal waveform modulation depth was reduced from a maximum of 47.7% to 17.3% at a center wavelength of 1053.328 nm. The experimental results show that the FM-to-AM conversion can be effectively suppressed in the spectral-broadened Nd:glass regenerative laser amplifier, which indicates that it has potential application as a preamplifier of large-scale laser facilities.
为了抑制钕玻璃再生激光放大器引起的调频到调幅（FM-to-AM）转换，通过理论模拟设计了一种双折射石英晶体，并将其插入再生放大器中。研制出了一种增益谱中具有约3.7的平顶区域的宽带钕玻璃再生激光放大器。采用全光纤前端系统产生脉宽为2 ns、光谱宽度约为0.5的整形脉冲，该脉冲通过两级相位调制器展宽。然后，激光脉冲由光谱展宽的再生放大器放大。在中心波长1053.328 nm处，放大后的输出时间波形调制深度从最大的47.7%降低到17.3%。实验结果表明，在光谱展宽的钕玻璃再生激光放大器中可以有效抑制FM-to-AM转换，这表明它作为大型激光装置的前置放大器具有潜在应用价值。
