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Maxim Fadeev

Publications and source records attributed to Maxim Fadeev.

3 recordsLinked to original sources

Influence of optical self-injection on statistical properties of laser-pulse interference

Pulsed optical self-injection markedly affects the emission characteristics of semiconductor lasers. In this work, we analyze its influence on the statistical properties of laser-pulse interference. We experimentally demonstrate that varying the arrival time of reflected optical pulses back into the laser cavity influences the phase-diffusion and induces an effect that, by analogy with external optical injection, we call phase locking. A comprehensive theoretical analysis of this phenomenon is also presented.

physics.optics

Optical-pumping attack on a quantum key distribution laser source

We report a new type of vulnerability in practical implementations of quantum key distribution systems. We show that it is possible to increase the pulse energy of a source laser diode not only by injection-locking it by external light near its emission wavelength of 1550 nm, but also by optically pumping it at a much shorter wavelength. We demonstrate 10% increase in pulse energy when exposing the laser diode to 1310-nm, 1.6-mW cw laser light via its fiber pigtail. This may allow an eavesdropper to steal the secret key. A possible countermeasure is to install broadband optical filters and isolators at the source's output and characterise them during the security certification.

quant-ph

Coherent detection schemes for subcarrier wave continuous variable quantum key distribution

We examine different methods to implement coherent detection in the subcarrier wave quantum key distribution (SCW QKD) systems. For classical wavefields, we present the models describing homodyne-type and heterodyne-type coherent detection schemes needed to extract information from the quadrature phase-coded multimode signals used in SCW QKD. Practical feasibility of the proposed schemes is corroborated by the experiments.

quant-ph