Schönbeck Axel, Thies Fabian, Schnabel Roman
Opt Lett. 2018 Jan 1;43(1):110-113. doi: 10.1364/OL.43.000110.
Strongly squeezed light at telecommunication wavelengths is a necessary resource for one-sided device-independent quantum key distribution via fiber networks. Reducing the optical pump power that is required for its generation will advance this quantum technology towards efficient out-of-laboratory operation. Here, we investigate the second-harmonic pump power requirement for parametric generation of continuous-wave squeezed vacuum states at 1550 nm in a state-of-the-art doubly resonant standing-wave periodically poled potassium titanyl phosphate cavity setup. We use coarse adjustment of the Gouy phase via the cavity length, together with temperature fine-tuning, for simultaneously achieving double resonance and (quasi) phase matching, and observe a squeeze factor of 13 dB at 1550 nm from just 12 mW of external pump power at 775 nm. We anticipate that optimizing the cavity coupler reflectivity will reduce the external pump power to 3 mW, without reducing the squeeze factor.
电信波长的强压缩光是通过光纤网络进行单边设备无关量子密钥分发的必要资源。降低其产生所需的光泵浦功率将推动这项量子技术朝着高效的实验室外运行发展。在此，我们研究了在最先进的双共振驻波周期性极化磷酸钛氧钾腔装置中，在1550纳米处参量产生连续波压缩真空态的二次谐波泵浦功率要求。我们通过腔长对古依相位进行粗调，并结合温度微调，以同时实现双共振和（准）相位匹配，并在1550纳米处从仅775纳米的12毫瓦外部泵浦功率中观察到13分贝的压缩因子。我们预计，优化腔耦合器反射率将把外部泵浦功率降低到3毫瓦，而不降低压缩因子。
