Fig. 5From: Autocompensating measurement-device-independent quantum cryptography in space division multiplexing optical fibersa Optical Fiber Delay (OFD) by using a PBS. b Autocompensating device and phase modulator for polarization encoding: photons coming from Charlie enter the local loops at Alice’s and Bob’s sites. There, a HWP rotated 45∘ degrees implement the appropriate autocompensating transformation. Next relative phases are introduced for state generationBack to article page