Open AccessLEO-to-ground polarization measurements aiming for space QKD using Small Optical TrAnsponder (SOTA)
Author(s) -
Alberto CarrascoCasado,
Hiroo Kunimori,
Hideki Takenaka,
Toshihiro Kubota,
Maki Akioka,
Tetsuharu Fuse,
Yoshinori Koyama,
Dimitar Kolev,
Yasushi Munemasa,
Morio Toyoshima
Publication year - 2016
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.24.012254
Subject(s) - quantum key distribution , physics , polarization (electrochemistry) , laser , quantum information science , optics , optical communication , free space optical communication , quantum channel , quantum cryptography , quantum , telecommunications , computer science , quantum information , photon , quantum entanglement , quantum mechanics , chemistry
Quantum communication, and more specifically Quantum Key Distribution (QKD), enables the transmission of information in a theoretically secure way, guaranteed by the laws of quantum physics. Although fiber-based QKD has been readily available since several years ago, a global quantum communication network will require the development of space links, which remains to be demonstrated. NICT launched a LEO satellite in 2014 carrying a lasercom terminal (SOTA), designed for in-orbit technological demonstrations. In this paper, we present the results of the campaign to measure the polarization characteristics of the SOTA laser sources after propagating from LEO to ground. The most-widely used property for encoding information in free-space QKD is the polarization, and especially the linear polarization. Therefore, studying its behavior in a realistic link is a fundamental step for proving the feasibility of space quantum communications. The results of the polarization preservation of two highly-polarized lasers are presented here, including the first-time measurement of a linearly-polarized source at λ = 976 nm and a circularly-polarized source at λ = 1549 nm from space using a realistic QKD-like receiver, installed in the Optical Ground Station at the NICT Headquarters, in Tokyo, Japan.