METHOD OF DETECTING PHOTON QUBITS ENCODED ON PHASES OF SUBCARRIERS OF FREQUENCIES φ = 0, π/4, π/2, 3π/4 Russian patent published in 2024 - IPC H04L9/08 

FIELD: electrical communication equipment.

SUBSTANCE: invention relates to communication, for use in optical communication equipment, for methods of processing optical information, including optical quantum computing, quantum communication and optical quantum cryptography systems. Method of detecting photonic qubits encoded on phases of subcarriers: ϕ = 0, π/4, π/2, 3π/4, includes separation of central mode of coherent multifrequency radiation at carrier frequency from signal subcarriers; central mode is sent to a phase modulator which modulates the input radiation of one of the phases of a randomly selected pair ϕ₀ = 0, π/2 or ϕ₀ = π/4, 3π/4; as a result of modulation, reference radiation is generated at subcarrier frequencies with selected phase ϕ₀; further, the subcarriers of the reference radiation are separated from the coherent multifrequency radiation at the carrier frequency; further, the signal and reference photonic qubits are mixed on a beam-splitter, at the outputs of which, when the selected bases coincide, one of two detectors is triggered, recording the result of constructive or destructive interference.

EFFECT: detection of photonic qubits encoded on phases of subcarriers in non-orthogonal bases of phases ϕ = 0, π/4, π/2, 3π/4.

1 cl, 1 dwg