Su Zikang, Cai Dajian, Jiang Hao, Wang Jintao, Wang Dawei, Guo Xiaojie, Li Zhaohui
Opt Lett. 2022 Mar 1;47(5):1287-1290. doi: 10.1364/OL.451670.
We develop an optical injection locking (OIL) based local oscillator (LO) regeneration for continuous variable quantum key distribution (CVQKD) by sending a weak polarization multiplexed pilot carrier from the transmitter. The OIL at the receiver has superior performance in terms of minimum input power and noise level at offset frequencies to the erbium-doped fiber amplifier (EDFA)-based scheme. The weak pilot carrier is recovered both in power and phase via the OIL while incurring little excess noise to the CVQKD system. The phase-locked LO enables heterodyne detection of a Gaussian modulated quantum signal with a simple data-aided phase recovery without pilot tone. The obtained parameters are compatible with a raw key rate of 0.83 Mbit/s in the asymptotic regime over a 22-km fiber transmission. The technique is expected to be used in more phase-sensitive quantum optical applications.
我们通过从发射机发送弱偏振复用导频载波，为连续变量量子密钥分发（CVQKD）开发了一种基于光注入锁定（OIL）的本地振荡器（LO）再生方法。与基于掺铒光纤放大器（EDFA）的方案相比，接收机处的光注入锁定在偏移频率下的最小输入功率和噪声水平方面具有卓越性能。通过光注入锁定，弱导频载波在功率和相位上均得以恢复，同时给CVQKD系统带来的额外噪声很小。锁相本地振荡器能够在无需导频音的情况下，通过简单的数据辅助相位恢复对高斯调制量子信号进行外差检测。在22公里光纤传输的渐近区域中，所获得的参数与0.83 Mbit/s的原始密钥率兼容。预计该技术将用于更多对相位敏感的量子光学应用中。
