Oam measurement device independent quantum key distribution system based on real-time tracking compensation and method thereof

An OAM measurement device independent quantum key distribution system based on real-time tracking compensation, wherein, comprising:

• a user side Alice, a user side Bob and a measuring unit;
• the user side Alice and the user side Bob are connected with the measuring unit through quantum channels:
• the measuring unit comprising:
• a first telescope system, a second telescope system, a first 50/50 beam splitter, a first polarization beam splitter, a pulse laser, a first reflector, a second reflector, a third reflector, a fourth reflector, a first M-Z interferometer, a second M-Z interferometer and a first single photon detector, a second single photon detector, a third single photon detector, a fourth single photon detector;
• when a pulse laser of the measuring unit emits a fundamental mode Gaussian beam, the fundamental mode Gaussian beam with the polarization mode of vertical polarization is reflected to a first 50/50 beam splitter and splitted into 2 beams through screening of the first polarization beam splitter, then is respectively reflected by the first reflector and the second reflector, and afterwards is collimated by the first telescope system and the second telescope system and is finally respectively transmitted to the user side Alice and the user side Bob through quantum channels;
• the user side Alice and the user side Bob respectively perform channel environment real-time monitoring, phase distortion compensation and orbital angular momentum encoding on the strong pulse laser from the measuring unit and then send the strong pulse laser to the test unit;
• when the first telescope system and the second telescope system of the measuring unit respectively receive signal pulses from a user side Alice and a user side Bob, the signal pulses are reflected by the first reflector and the second reflector, then are interfered at a third 50/50 beam splitter, the interfered pulses respectively enter a first M-Z interferometer and a second M-Z interferometer after being respectively reflected by the third reflector and the fourth reflector;
• and then the pulses enter the first single photon detector, the second single photon detector, the third single photon detector and the fourth single photon detector to cause response and output measuring results after being separated by the first M-Z interferometer and the second M-Z interferometer;
• and the user side Alice and the user side Bob locally generate consistent keys after the processes of base comparison, key agreement and the like according to the measured response condition.