Real-time phase tracking in single-photon interferometers

a paper written in Quantum Cryptography group at the Department of Electronics and Telecommunications

Vadim Makarov, Alexey Brylevski, and Dag R. Hjelme, "Real-time phase tracking in single-photon interferometers," Journal of Applied Optics 43, 4385-4392 (2004).


A new technique for phase tracking in quantum cryptography systems is proposed that adjusts phase in an optimal way, using only as many photon counts as necessary. We derive an upper bound on the number of photons that need to be registered during phase adjustment to achieve a given phase accuracy. It turns out that most quantum cryptosystems can successfully track phase on a single-photon level, entirely with software, without any additional hardware components or extensive phase-stabilization measures. The technique is tested experimentally on a quantum cryptosystem.


PDF (370KB). This file also contains a later addendum discussing two assumptions taken for granted in the paper.

See also: This paper in publisher's (OSA's) database


This paper is based on the results of Alexey Brylevski's master thesis.
Vadim Makarov