Ast Stefan, Mehmet Moritz, Schnabel Roman
Max Planck Institute for Gravitational Physics, Albert Einstein Institute, Leibniz Universität Hannover, Hannover, Germany.
Opt Express. 2013 Jun 3;21(11):13572-9. doi: 10.1364/OE.21.013572.
We report the generation of squeezed vacuum states of light at 1550 nm with a broadband quantum noise reduction of up to 4.8 dB ranging from 5 MHz to 1.2 GHz sideband frequency. We used a custom-designed 2.6 mm long biconvex periodically-poled potassium titanyl phosphate (PPKTP) crystal. It featured reflectively coated end surfaces, 2.26 GHz of linewidth and generated the squeezing via optical parametric amplification. Two homodyne detectors with different quantum efficiencies and bandwidths were used to characterize the non-classical noise suppression. We measured squeezing values of up to 4.8 dB from 5 to 100 MHz and up to 3 dB from 100 MHz to 1.2 GHz. The squeezed vacuum measurements were limited by detection loss. We propose an improved detection scheme to measure up to 10 dB squeezing over 1 GHz. Our results of GHz bandwidth squeezed light generation provide new prospects for high-speed quantum key distribution.
我们报告了在1550纳米波长处产生光的压缩真空态，其宽带量子噪声降低高达4.8分贝，边带频率范围从5兆赫兹到1.2吉赫兹。我们使用了定制设计的2.6毫米长双凸面周期性极化钛酸钡钾（PPKTP）晶体。它具有反射涂层的端面、2.26吉赫兹的线宽，并通过光学参量放大产生压缩。使用两个具有不同量子效率和带宽的零差探测器来表征非经典噪声抑制。我们测量到从5到100兆赫兹的压缩值高达4.8分贝，从100兆赫兹到1.2吉赫兹的压缩值高达3分贝。压缩真空测量受探测损耗限制。我们提出一种改进的探测方案，以在1吉赫兹范围内测量高达10分贝的压缩。我们关于吉赫兹带宽压缩光产生的结果为高速量子密钥分发提供了新的前景。
