Quantum Key Distribution Transmitter Chip Based on Hybrid-integration of Silica and Lithium Niobates

2021 ◽  
Author(s):  
Xiao Li ◽  
Liang-Liang Wang ◽  
Jia-shun Zhang ◽  
Wei Chen ◽  
Yue Wang ◽  
...  
Keyword(s):  
Repetition Rate ◽  
Quantum Key Distribution ◽  
Directional Coupler ◽  
Delay Line ◽  
Light Wave ◽  
Key Distribution ◽  
Hybrid Integration ◽  
Phase Encoding ◽  
Fast Phase ◽  
Electro Optic

Abstract A quantum key distribution transmitter chip based on hybrid‐integration of silica planar light‐wave circuit (PLC) and lithium niobates (LN) modulator PLC is presented. The silica part consists of a tunable directional coupler and 400 ps delay line, and the LN part is made up of a Y‐branch, with electro‐optic modulators on both arms. The two parts are facet‐coupled to form an asymmetric Mach‐Zehnder interferometer. We have successfully encoded and decoded four BB84 states at 156.25 MHz repetition rate. Fast phase‐encoding of 0 or π has been achieved, with interference fringe visibilities 78.53% and 82.68% for state |+> and |‐>, respectively. With the aid of an extra off‐chip LN intensity modulator, two time‐bin states have been prepared and the extinction ratios are 18.65 dB and 15.46 dB for state |0> and |1>, respectively.

scholarly journals Demonstration of high-speed and low-complexity continuous variable quantum key distribution system with local local oscillator

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Shengjun Ren ◽  
Shuai Yang ◽  
Adrian Wonfor ◽  
Ian White ◽  
Richard Penty
Keyword(s):  
Distribution System ◽  
Repetition Rate ◽  
Quantum Key Distribution ◽  
Optimization Technique ◽  
Key Distribution ◽  
Local Oscillator ◽  
Continuous Variable ◽  
Noise Model ◽  
System Level ◽  
Excess Noise

AbstractWe present an experimental demonstration of the feasibility of the first 20 + Mb/s Gaussian modulated coherent state continuous variable quantum key distribution system with a locally generated local oscillator at the receiver (LLO-CVQKD). To increase the signal repetition rate, and hence the potential secure key rate, we equip our system with high-performance, wideband devices and design the components to support high repetition rate operation. We have successfully trialed the signal repetition rate as high as 500 MHz. To reduce the system complexity and correct for any phase shift during transmission, reference pulses are interleaved with quantum signals at Alice. Customized monitoring software has been developed, allowing all parameters to be controlled in real-time without any physical setup modification. We introduce a system-level noise model analysis at high bandwidth and propose a new ‘combined-optimization’ technique to optimize system parameters simultaneously to high precision. We use the measured excess noise, to predict that the system is capable of realizing a record 26.9 Mb/s key generation in the asymptotic regime over a 15 km signal mode fibre. We further demonstrate the potential for an even faster implementation.

Urban QKD test for phase and polarization encoding devices

2017 ◽  
Vol 15 (08) ◽  
pp. 1740018
Author(s):  
Alan Kanapin ◽  
Alexander Duplinskiy ◽  
Alexander Sokolov ◽  
Sergey Vorobey ◽  
Alexander Miller ◽  
...  
Keyword(s):  
Bit Error Rate ◽  
Quantum Key Distribution ◽  
Key Distribution ◽  
Optical Scheme ◽  
Communication Line ◽  
Key Generation ◽  
Phase Encoding ◽  
Fiber Communication ◽  
Quantum Bit ◽  
Polarization Encoding

In this work, the results of quantum key distribution through an urban fiber communication line with a length of 30.6[Formula: see text]km and losses of 11.7[Formula: see text]dB, obtained by both phase and polarization encoding-based devices, are presented. For phase encoding, a two-pass auto-compensating optical scheme, commonly called “plug&play”, was used. For polarization encoding, a self-developed unconventional optical scheme was made. A continuous key distribution with a sifted key generation rate of 1.0[Formula: see text]kbit/s and a quantum bit error rate of 5.7% was implemented when using “plug&play” device, whereas 0.1[Formula: see text]kbit/s and 5.5% was observed when using one with polarization encoding. The features and conveniences of both implementations are discussed.

An autobias control system for the electro—optic modulator used in a quantum key distribution system

2014 ◽  
Vol 23 (8) ◽  
pp. 080304 ◽  
Author(s):  
Wen-Fen Chen ◽  
Zheng-Jun Wei ◽  
Li Guo ◽  
Li-Yan Hou ◽  
Geng Wang ◽  
...  
Keyword(s):  
Control System ◽  
Distribution System ◽  
Quantum Key Distribution ◽  
Key Distribution ◽  
Electro Optic ◽  
Electro Optic Modulator

Tunable electro-optic polarization modulator for quantum key distribution applications

2004 ◽  
Vol 234 (1-6) ◽  
pp. 203-210 ◽  
Author(s):  
Nikita Yu. Gordeev ◽  
Karen J. Gordon ◽  
Gerald S. Buller
Keyword(s):  
Quantum Key Distribution ◽  
Key Distribution ◽  
Polarization Modulator ◽  
Electro Optic

scholarly journals Quantum key distribution based on phase encoding and polarization measurement

2007 ◽  
Vol 32 (6) ◽  
pp. 698 ◽  
Author(s):  
Hai-Qiang Ma ◽  
Jian-Ling Zhao ◽  
Ling-An Wu
Keyword(s):  
Quantum Key Distribution ◽  
Key Distribution ◽  
Polarization Measurement ◽  
Phase Encoding

Design of a high-repetition rate photon source in a quantum key distribution system

2012 ◽  
Vol 56 (9) ◽  
pp. 1-7
Author(s):  
Jian Wang ◽  
Ke Cui ◽  
ChunLi Luo ◽  
HongFei Zhang ◽  
Lei Zhou ◽  
...  
Keyword(s):  
Distribution System ◽  
Repetition Rate ◽  
Quantum Key Distribution ◽  
Key Distribution ◽  
High Repetition Rate ◽  
High Repetition ◽  
Photon Source

scholarly journals Proof-of-principle demonstration of semi-quantum key distribution based on the Mirror protocol

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Siyu Han ◽  
Yutao Huang ◽  
Shang Mi ◽  
Xiaojuan Qin ◽  
Jindong Wang ◽  
...  
Keyword(s):  
Quantum Key Distribution ◽  
Key Distribution ◽  
Future Research ◽  
Experimental Demonstration ◽  
Phase Encoding ◽  
Quantum Bit ◽  
Selective Modulation ◽  
Secret Keys ◽  
Shared Secret ◽  
Proof Of Principle

AbstractSemi-quantum key distribution (SQKD) is used to establish a string of shared secret keys between a quantum party and a classical party. Here, we report the first proof-of-principle experimental demonstration of SQKD based on the Mirror protocol, which is the most experimentally feasible SQKD protocol, and equipped with time-phase encoding scheme employing the method of selective modulation. The experiment was performed at a repetition frequency of 62.5 MHz and a high raw key rate arrived at 69.8 kbps, and the average quantum bit error rate was found to be 4.56% and 2.78% for the “SWAP-x-Z” ($\mathrm{x}\in \{01,10\}$ x ∈ { 01 , 10 } ) and the “CTRL-X”, respectively. The results demonstrate the feasibility of our system, and this study is helpful for future research on SQKD experiments.

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