He Deyong

Countermeasure against probabilistic blinding attack in practical quantum key distribution systems

In a practical quantum key distribution (QKD) system, imperfect equipment, especially the single-photon detector, can be eavesdropped on by a blinding attack. However, the original blinding attack may be discovered by directly detecting the current. In this paper, we propose a probabilistic blinding attack model, where Eve probabilistically applies a blinding attack without being caught by using only an existing intuitive countermeasure. More precisely, our countermeasure solves the problem of how to define the bound in the limitation of precision of current detection, and then we prove security of the practical system by considering the current parameter. Meanwhile, we discuss the bound of the quantum bit error rate (QBER) introduced by Eve, by which Eve can acquire information without the countermeasure.

High accuracy laser range sensor system based on the self-mixing effect in a single mode VCSEL

A miniaturized laser range sensor system based on the self-mixing effect in a single mode VCSEL is proposed. The system accuracy is better than 2mm and distance is from 100mm to 1000mm with 0.1s sampling time.

New Laser Doppler Velocimetry with Wide Dynamic Range and Clear Directional Discrimination

We present a new laser Doppler velocimetry based on self-mixing effect using a single longitudinal-mode vertical-cavity surface-emitting laser modulated by a dynamic triangular current. It can indicate the direction of velocity without ambiguity in a wide dynamic range of 5.2–479.9 mm/s. The accuracy of velocity measurement is better than 3.1% in the whole velocity range when a diffusing target is used for measurements. More interestingly, it works very well on different diffusing surfaces, even on a black glossy photographic paper.