Time-phase encoding apparatus and method, and quantum communication system

Abstract

A time-phase encoding apparatus and method, and a quantum communication system. The apparatus comprises: a first polarization operation module (100), a second polarization operation module (200), and an unequal-arm polarization control interferometer (300) which are connected in series; the two polarization operation modules each comprise a polarization control optical path and a phase modulator; the unequal-arm polarization control interferometer comprises a fifth optical coupling unit (211), a sixth optical coupling unit (214), and transmission optical paths having unequal optical path lengths. By setting an included angle between intrinsic polarization states of the polarization control optical paths in the two polarization operation modules and an included angle between the intrinsic polarization state of the polarization control optical path in the first polarization operation module and an intrinsic polarization state of the unequal-arm polarization control interferometer, the requirements of various quantum communication protocols are met. Six polarization-encoded quantum states in three bases are generated by using the two polarization operation modules, and then the polarization-encoded quantum states are converted into time-phase-encoded quantum states by using the unequal-arm polarization control interferometer, thereby achieving generation of X- / Y-basis phase quantum states and Z-basis time quantum states.

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