Three-dimensional echo distribution analysis of multi-band and oblique Gaussian beams propagating through cat-eye optical system

Abstract

The cat-eye effect in optical systems enables active laser detection at long distances and high orientation precision. However, few studies focus on the influence of a multi-band laser with a large incident angle on the echo distribution. This study proposes a three-dimensional echo distribution calculation model of an obliquely incident multi-band laser based on the Collins diffraction integral formula and aperture function expansion as the sum of complex Gaussian functions. The echo distributions for different detection ranges are calculated by coupling the size of the detector in a cat-eye optical system into the model. In the numerical simulation, the influences of laser wavelength, incident angle, and target detector parameter are quantitatively analysed by introducing a target-missing quantity of echo spot and peak light intensity. The results show that the peak light intensity decreases with an increase in incident laser wavelength. When the incident angle increases to a particular value, the peak light intensity decreases sharply, and the target-missing quantity of the echo spot centroid is positively correlated with the incident angle. We can effectively extract important information, such as the working band and detector size, from the cat-eye target echo using this model and provide a trajectory prediction theory for the active detection of a cat-eye target moving at high speed.