Performance improvement of free-space continuous-variable quantum key distribution with an adaptive optics unit

We propose a method to enhance the performance of the free-space continuous-variable quantum key distribution (FSCVQKD) by utilizing an adaptive optics (AO) unit at the receiver’s side to suppress wavefront distortions caused by high-order wavefront aberrations for fault-tolerant detection. Benefiting from the AO unit, the high-order wavefront aberrations can be corrected and thus effectively improve the mixing efficiency of homodyne detection, which enhances the performance of FSCVQKD. Considering the fact that the closed-loop control bandwidth of AO unit and the atmospheric coherence length have an important effect in performance improvement for FSCVQKD, in this paper, we analyze the performance of our protocol with AO unit under different closed-loop control bandwidths and atmospheric coherence lengths, respectively. The analysis is performed by considering the three specific scenarios of turbulence which are frequent challenges in FSCVQKD protocol, namely beam wandering, randomly blocked and log-normal distribution. In addition, we also study the impact of AO-added noise on our protocol. Simulation results show that all in the beam wandering case, the randomly blocked case and the log-normal distribution, the use of AO unit can enhance the performance of FSCVQKD protocol by adjusting the closed-loop control bandwidth of AO unit and the atmospheric coherence length in appropriate ranges with the case of fixed Greenwood frequency in the presence of AO-added noise.

[1]  Yudong Zhang,et al.  Experiments of high-resolution retinal imaging with adaptive optics , 2004, SPIE/COS Photonics Asia.

[2]  Seth Lloyd,et al.  Gaussian quantum information , 2011, 1110.3234.

[3]  H. Li,et al.  Superconducting Nanowire Single-Photon Detector With a System Detection Efficiency Over 80% at 940-nm Wavelength , 2016, IEEE Photonics Journal.

[4]  Guangjun Wen,et al.  Experimental demonstration of a magnetically tunable ferrite based metamaterial absorber. , 2014, Optics express.

[5]  Ying Guo,et al.  Entanglement-distillation attack on continuous-variable quantum key distribution in a turbulent atmospheric channel , 2017 .

[6]  Minghao Wang,et al.  Pyramid wavefront sensor using a sequential operation method , 2015 .

[7]  Chao Liu,et al.  Performance evaluation of adaptive optics for atmospheric coherent laser communications. , 2014, Optics express.

[8]  H. Bechmann-Pasquinucci,et al.  Quantum cryptography , 2001, quant-ph/0101098.

[9]  W. Vogel,et al.  Toward global quantum communication: beam wandering preserves nonclassicality. , 2011, Physical review letters.

[10]  Jiang Dagang,et al.  Effectiveness of adaptive optics system in satellite-to-ground coherent optical communication. , 2014, Optics express.

[11]  C. Rao,et al.  Laboratory demonstrations on a pyramid wavefront sensor without modulation for closed-loop adaptive optics system. , 2011, Optics express.

[12]  T. Ralph,et al.  Continuous variable quantum cryptography , 1999, quant-ph/9907073.

[13]  Zoran Sodnik,et al.  Adaptive optics for satellite-to-ground laser communication at the 1m Telescope of the ESA Optical Ground Station, Tenerife, Spain , 2010, Astronomical Telescopes + Instrumentation.

[14]  Eleni Diamanti,et al.  Experimental demonstration of long-distance continuous-variable quantum key distribution , 2012, Nature Photonics.

[15]  W. Vogel,et al.  Atmospheric Quantum Channels with Weak and Strong Turbulence. , 2016, Physical review letters.

[16]  Peng Huang,et al.  Continuous-variable quantum key distribution with 1 Mbps secure key rate. , 2015, Optics express.

[17]  N. Cerf,et al.  Unconditional optimality of Gaussian attacks against continuous-variable quantum key distribution. , 2006, Physical Review Letters.

[18]  Chao Liu,et al.  Adaptive optics for the free-space coherent optical communications , 2016 .

[19]  Wei Liu,et al.  Stochastic parallel gradient descent laser beam control algorithm for atmospheric compensation in free space optical communication , 2014 .

[20]  Wei Liu,et al.  Performance analysis of a coherent free space optical communication system based on experiment. , 2017, Optics express.

[21]  Wei Liu,et al.  Bit error rate analysis with real-time pointing errors correction in free space optical communication systems , 2014 .

[22]  Yahya Rahmat-Samii,et al.  Technology Trends and Challenges of Antennas for Satellite Communication Systems , 2015, IEEE Transactions on Antennas and Propagation.

[23]  Hong Guo,et al.  Performance of phase compensated coherent free space optical communications through non-Kolmogorov turbulence , 2011 .

[24]  Ming Li,et al.  Coherent free space optics communications over the maritime atmosphere with use of adaptive optics for beam wavefront correction. , 2015, Applied optics.

[25]  Ekert,et al.  Quantum cryptography based on Bell's theorem. , 1991, Physical review letters.

[26]  R. Tyson,et al.  Adaptive optics and ground-to-space laser communications. , 1996, Applied optics.

[27]  E. Diamanti,et al.  Improvement of continuous-variable quantum key distribution systems by using optical preamplifiers , 2008, 0812.4314.

[28]  W. Vogel,et al.  Quantum light in the turbulent atmosphere , 2009, 0902.4187.

[29]  P. Grangier,et al.  Continuous variable quantum cryptography using coherent states. , 2001, Physical review letters.

[30]  Zabih Ghassemlooy,et al.  Experimental characterization and mitigation of turbulence induced signal fades within an ad hoc FSO network. , 2014, Optics express.

[31]  N. Cerf,et al.  Quantum key distribution using gaussian-modulated coherent states , 2003, Nature.

[32]  Gilles Brassard,et al.  Quantum cryptography: Public key distribution and coin tossing , 2014, Theor. Comput. Sci..

[33]  Richard J. Hughes,et al.  Effects of propagation through atmospheric turbulence on photon statistics , 2004 .

[34]  Lo,et al.  Unconditional security of quantum key distribution over arbitrarily long distances , 1999, Science.

[35]  R. Fante.  Electromagnetic beam propagation in turbulent media , 1975, Proceedings of the IEEE.

[36]  R. Fante,et al.  Electromagnetic beam propagation in turbulent media: An update , 1980, Proceedings of the IEEE.

[37]  Aniceto Belmonte,et al.  Influence of atmospheric phase compensation on optical heterodyne power measurements. , 2008, Optics express.

[38]  Tao Wang,et al.  Field demonstration of a continuous-variable quantum key distribution network. , 2016, Optics letters.

[39]  S. McLaughlin,et al.  Quantum key distribution over 25 km with an all-fiber continuous-variable system , 2007, 0706.4255.

[40]  Wei Liu,et al.  Performance evaluation of coherent free space optical communications with a double-stage fast-steering-mirror adaptive optics system depending on the Greenwood frequency. , 2016, Optics express.

[41]  Hong Guo,et al.  Performance of Coherent BPSK Systems Using Phase Compensation and Diversity Techniques , 2010, 2010 IEEE Global Telecommunications Conference GLOBECOM 2010.

[42]  Liren Liu,et al.  Performance analysis of pupil-matching optical differential receivers in space-to-ground laser communication. , 2014, Applied optics.

[43]  H. Lo,et al.  Experimental study on the Gaussian-modulated coherent-state quantum key distribution over standard telecommunication fibers , 2007, 0709.3666.

[44]  Wenyue Zhu,et al.  Signal to noise ratio of free space homodyne coherent optical communication after adaptive optics compensation , 2015 .

[45]  Peng Huang,et al.  High-speed continuous-variable quantum key distribution without sending a local oscillator. , 2015, Optics letters.

[46]  Wei Liu,et al.  Free space optical communication performance analysis with focal plane based wavefront measurement , 2013 .

[47]  Xinyue Liu,et al.  Closed-loop adaptive optics system with a single liquid crystal spatial light modulator. , 2014, Optics express.

[48]  Vladyslav C. Usenko,et al.  Entanglement of Gaussian states and the applicability to quantum key distribution over fading channels , 2012, 1208.4307.

[49]  Adolfo Comerón,et al.  Phase compensation considerations on coherent free-space laser communications system , 2007, SPIE Security + Defence.

[50]  Li Xuan,et al.  Open-loop control of liquid-crystal spatial light modulators for vertical atmospheric turbulence wavefront correction. , 2011, Applied optics.

[51]  Peng Huang,et al.  Long-distance continuous-variable quantum key distribution by controlling excess noise , 2016, Scientific Reports.

[52]  V. Scarani,et al.  The security of practical quantum key distribution , 2008, 0802.4155.

[53]  Radim Filip,et al.  Continuous-variable entanglement distillation of non-Gaussian mixed states , 2010, 1002.0280.

[54]  M. Hillery.  Quantum cryptography with squeezed states , 1999, quant-ph/9909006.