Visualization 1: Free space optical secret key agreement EndoHiroyuki FujiwaraMikio KitamuraMitsuo TsuzukiOrie ItoToshiyuki ShimizuRyosuke TakeokaMasahiro SasakiMasahide 2018 This movie presents the variations of experimental final key rate and the histograms of the demodulated sequences during 27 hours from 18:00 on 11 June. See also Fig. 10 in our companion paper ``Free space optical secret key agreement". The histogram disappears in the case where the frame synchronization failed due to low received power.