星地量子通信关键技术及地面实验

发布时间：2018-06-25 18:19

本文选题：量子通信 + 自由空间　；参考：《中国科学技术大学》2014年博士论文

【摘要】：实现超远距离量子通信一直是量子信息领域的难点之一。由于光纤固有衰减影响,在光纤信道中量子通信的距离已接近极限,而光子在通过大气层后的外层空间衰减几乎为零。于是基于空间平台中转的星地量子通信成为实现全球化量子通信最切实可行的方案之一。本文作者在博士阶段的主要工作,就是围绕自由空间量子通信在链路建设和时间同步方面的关键技术进行研究,并以这些关键技术为突破点,完成了远程双光子干涉和白天量子密钥分发等实验。在链路建设方面,本人研究了窄光束发射和高精度光束自动跟踪技术,所研制系统的远场发散角达到了 12 μrad,跟踪误差小于3 μrad。在97 km光学链路中,链路总效率达到了 35dB;另外,在52 km光学链路(单模)中,链路总效率最高达到了 30 dB。在时间同步方面,本人负责了外同步光系统,并开发了一套用于进行远程时间同步的数据处理软件。在102 km链路的实验中,同步系统精度达到了1 ns,提高了实验的信噪比;而数据处理软件也应用在了数个实验中。在这些技术的基础上,本人参与了 97 km量子隐形传态实验,负责接收端具体工作,实验说明了基于卫星的超长距离的量子隐形传态的可行性。本人还组织完成了 220 m自由空间的双光子干涉实验和52 km白天量子密钥分发实验。其中,双光子干涉实验是基于纠缠的远距离量子中继和量子通信的基础。白天量子密钥分发实验是将来进行不需可信中继的量子密钥分发实验的技术积累,可以实现自由空间与光纤通道的无缝连接,也是进行全时段自由空间量子实验的尝试。
[Abstract]:It is one of the difficulties in quantum information field to realize quantum communication over long distance. Due to the influence of the intrinsic attenuation of the optical fiber, the distance of quantum communication in the fiber channel is close to the limit, while the photon attenuation in the outer space after passing through the atmosphere is almost zero. Therefore, satellite-ground quantum communication based on space platform transfer becomes one of the most feasible schemes to realize global quantum communication. The author's main work in the Ph.D. phase is to study the key technologies of free space quantum communication in link construction and time synchronization, and take these key technologies as the breakthrough point. Experiments such as remote two-photon interference and daytime quantum key distribution are carried out. In the aspect of link construction, I have studied the technology of narrow beam emission and high precision beam automatic tracking. The far field divergence angle of the developed system is 12 渭 radand the tracking error is less than 3 渭 rad. In the 97 km optical link, the total link efficiency is 35 dB, and in the 52 km optical link (single mode), the maximum link efficiency is 30 dB. In the aspect of time synchronization, I take charge of the external synchronous optical system and develop a set of data processing software for remote time synchronization. In the experiment of 102km link, the precision of synchronization system is up to 1ns, which improves the signal-to-noise ratio (SNR) of the experiment, and the data processing software is also used in several experiments. On the basis of these techniques, I have participated in the 97 km quantum teleportation experiment, which is responsible for the specific work of the receiver. The experiment shows the feasibility of the super-long distance quantum teleportation based on satellite. I have also completed the two-photon interference experiment in 220m free space and the 52km daytime quantum key distribution experiment. The two-photon interference experiment is the basis of quantum relay and quantum communication based on entanglement. The daytime quantum key distribution experiment is a technique accumulation of quantum key distribution experiment without trusted relay in the future. It can realize the seamless connection between free space and fiber channel, and it is also an attempt to carry out free space quantum experiment in full time.
【学位授予单位】：中国科学技术大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：O413;TN918

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