Experimental Results of Polarization Characteristics Measurements through Satellite-to-Ground Propagation Paths toward Satellite Quantum Key Distribution

摘要

The polarization characteristics of a laser source from space were measured through space-to-ground atmospheric transmission paths. An existing Japanese laser communication satellite and the NICT's optical ground station were used to measure Stokes parameters and the degree of polarization of the laser beam transmitted from the satellite. As a result, the polarization was preserved within an rms error of 1.6°, and the degree of polarization was 99.4 ± 4.4% through the space-to-ground atmosphere. These results contribute to the link estimation for quantum key distribution via satellites and provide the potential for enhancements in quantum cryptography worldwide in the future.