Enhanced signal-to-noise ratio of array imaging using quantum state engineering

Abstract

Laser active detection is a remote sensing technology that utilizes laser beams to detect various attributes of a target such as distance, orientation, height, and speed. The direct detection Signal-to-Noise Ratio (SNR) achieved by traditional array imaging systems is usually unsatisfactory because of different types of interferences, including backscattering effects and background noise. Related to this, the performance of existing methods for noise filtering are bounded by the classical detection signal-to-noise ratio. In particular, and there is no effective filtering method when the wavelength of the signal and noise is the same. To address this challenge, this study presents a novel approach to enhancing the Signal-to-Noise Ratio (SNR) of array imaging through the use of quantum state engineering. At the transmitter, we modulate the signal photons with orbital angular momentum to distinguish them from the photons of noise without orbital angular momentum. This modulation makes the signal and noise have differences in spatial intensity distribution. Due to this spatial difference, the signal and noise can be non-destructively separated after passing through the filter at the receiver, which gives enhanced SNR. The results show that this method can effectively filter out the noise with the same wavelength as the signal, and can improve the performance of array imaging detection.