Laser intensity noise suppression for preparing audio-frequency squeezed vacuum state of light
Laser intensity noise suppression for preparing audio-frequency squeezed vacuum state of light
复制标题
制备音频压缩真空光态的激光强度噪声抑制
DOI：
10.3390/app10041415
复制
发表时间：
2020
期刊：
影响因子：
--
通讯作者：
Junmin WANG
中科院分区：
文献类型：
--
作者：
Lele BAI;Xin WEN;Yulin YANG;Jun HE;Junmin WANG
激光强噪声抑制对基于亚阈值光参量振荡器（OPO）的音频压缩真空光态的制备和表征具有重要影响。我们利用相应的声光调制器（AOM）实现了两个反馈回路，以稳定795 nm近红外（NIR）基频激光和397.5 nm腔增强倍频产生的紫外（UV）激光的强度。795 nm近红外光束半小时典型峰间激光强度波动从±7.45%提高到±0.06%，397.5 nm紫外光束从±9.04%提高到±0.05%，带宽为~10 kHz。在3~9 kHz的分析频率范围内，用PPKTP晶体制备的亚阈值OPO在795 nm处的压缩真空态的压缩电平从−3.3提高到−4.0 dB。
Laser intensity noise suppression has essential effects on preparation and characterization of the audio-frequency squeezed vacuum state of light based on a sub-threshold optical parametric oscillator (OPO). We have implemented two feedback loops by using relevant acousto-optical modulators (AOM) to stabilize the intensity of 795-nm near infrared (NIR) fundamental laser and 397.5-nm ultraviolet (UV) laser generated by cavity-enhanced frequency doubling. Typical peak-to-peak laser intensity fluctuation with a bandwidth of ~10 kHz in a half hour has been improved from ±7.45% to ±0.06% for 795-nm NIR laser beam, and from ±9.04% to ±0.05% for 397.5-nm UV laser beam, respectively. The squeezing level of the squeezed vacuum state at 795 nm prepared by the sub-threshold OPO with a PPKTP crystal has been improved from −3.3 to −4.0 dB around 3~9 kHz of analysis frequency range.