Design and test of optical payload for polarization encoded QKD for nanosatellites

Jaya Sagar*, Elliott Hastings, Peide Zhang, Milan Stefko, David Lowndes, Daniel Oi, John Rarity, Siddarth K. Joshi

*Corresponding author for this work

Research output: Chapter in Book/Report/Conference proceedingConference Contribution (Conference Proceeding)

3 Citations (Scopus)

Abstract

Satellite based Quantum Key Distribution (QKD) in Low Earth Orbit (LEO) is currently the only viable technology to span thousands of kilometres. Since the typical overhead pass of a satellite lasts for a few minutes, it is crucial to increase the the signal rate to maximise the secret key length. For the QUARC CubeSat mission due to be launched within two years, we are designing a dual wavelength, weak-coherent-pulse decoy-state Bennett-Brassard '84 (WCP DS BB84) QKD source. The optical payload is designed in a 12×9×5cm3 bespoke aluminium casing. The Discrete Variable QKD Source consists of two symmetric sources operating at 785 nm and 808 nm. The laser diodes are fixed to produce Horizontal,Vertical, Diagonal, and Anti-diagonal (H,V,D,A) polarisation respectively, which are combined and attenuated to a mean photon number of 0.3 and 0.5 photons/pulse. We ensure that the source is secure against most side channel attacks by spatially mode filtering the output beam and characterising their spectral and temporal characterstics. The extinction ratio of the source contributes to the intrinsic Qubit Error Rate(QBER) with 0.817±0.001%. This source operates at 200MHz, which is enough to provide secure key rates of a few kilo bits per second despite 40 dB of estimated loss in the free space channel.1

Original languageEnglish
Title of host publicationQuantum Technology
Subtitle of host publicationDriving Commercialisation of an Enabling Science III
EditorsMiles J. Padgett, Kai Bongs, Alessandro Fedrizzi, Alberto Politi
PublisherSPIE - The International Society for Optical Engineering
ISBN (Electronic)9781510657427
DOIs
Publication statusPublished - 2023
EventQuantum Technology: Driving Commercialisation of an Enabling Science III 2022 - Birmingham, United Kingdom
Duration: 7 Dec 20228 Dec 2022

Publication series

NameProceedings of SPIE - The International Society for Optical Engineering
Volume12335
ISSN (Print)0277-786X
ISSN (Electronic)1996-756X

Conference

ConferenceQuantum Technology: Driving Commercialisation of an Enabling Science III 2022
Country/TerritoryUnited Kingdom
CityBirmingham
Period7/12/228/12/22

Bibliographical note

Publisher Copyright:
© COPYRIGHT SPIE. Downloading of the abstract is permitted for personal use only.

Fingerprint

Dive into the research topics of 'Design and test of optical payload for polarization encoded QKD for nanosatellites'. Together they form a unique fingerprint.

Cite this