Pseudorandom modulation quantum secured lidar

A new lidar scheme called pseudorandom modulation quantum secured lidar is proposed. The position and polarization of the photon are randomly modulated through electro-optic modulators controlled by pseudorandom codes to realize ranging and security. Using this ability to obtain the target distance is secure against the most primitive, intercept-resend attack, popularly known as “jamming”. In order to jam our lidar system, the target has to disturb the delicate quantum state of the ranging photons, thus the statistical errors will be introduced, which can reveal the jamming activity. The formulas for estimating the signal-to-noise of our system are derived both in the presence and absence of jammers. Simulation result shows that, when there are no jammers, the range accuracy of centimeter level is obtained, and the observed range accuracy of the experiment is in agreement with this simulation value. However, the error of the received polarization can be viewed as random noise, which will descend the signal-to-noise ratio, and further decline the distance accuracy. The experimental results show that our system has a better ranging and anti-attack ability.