Figure 4From: Proof-of-principle demonstration of semi-quantum key distribution based on the Mirror protocol(a) The forward and backward optical path of the “CTRL-X” operation. (b)The forward and backward optical path of the “SWAP-x-Z” (\(\mathrm{x}\in \{01,10\}\)) operation. ISO: isolator, PC: polarization controller, VOA: variable attenuator, PG: electrical pulse generatorBack to article page