采用连续单频1.56 μm激光光源作为泵浦光,通过周期极化铌酸锂晶体外腔倍频过程实验制备出位于原子吸收波线的780 nm明亮振幅压缩态光场。在利用2个模清洁器过滤基频光的强度噪声、使之在分析频率4 MHz处达到散粒噪声的基础上,利用谐振倍频获得输出功率为10 mW、转换效率达40％的倍频光,实测的780 nm明亮振幅压缩光的压缩度为0.6 dB。

Bright amplitude squeezed light at 780 nm that was the D2 line of rubidium atom was generated from a frequency doubler with a periodically poled lithium niobate crystal. The frequency doubler was by a continues-wave single frequency 1.56 μm fiber laser. Based on the intensity noise of fiber laser was suppressed by two mode cleaners and reached to the shot-noise-limit at the analysis frequency of 4 MHz. At the pump power of 25 mW,the output power of 780 nm was 10 mW with the conversion efficiency of 40％,and the measured bright amplitude squeezed state at 780 nm was 0.6 dB.