Laser protection performance of a wavefront encoding imaging system with a tangent phase mask

Wavefront encoding is an efficient way to extend the depth of focus of optical imaging systems, and its core component, the phase mask, determines its performance in extending the depth of focus. It is worth noting that wavefront coding technology is also an important method for laser protection. On the one hand, its optical field modulation effect realizes the redistribution of laser energy at the imaging plane, reduces the maximum single-pixel received power, and improves the laser blinding protection capability of the imaging system; on the other hand, its out-of-focus imaging plane can reduce the echo detection received power, and achieves the goal of improving the laser reconnaissance protection capability while ensuring the imaging quality. This article presents a laser transmission model for the tangent phase plate wavefront coding imaging system while exploring its protective performance at varying defocus distances to verify its laser protection potential. The findings show that the system offers efficient protective capabilities, as the maximum single-pixel receiving power decreases by an order of magnitude, and the echo detection receiving power reduces nearly three orders of magnitude. Further, the study assesses the protective performance of the system at different propagation distances. The results indicate that when propagation distances vary between 100 m and 10,000 m, the maximum single-pixel receiving power of the wavefront coding imaging system decreases rapidly and then stabilizes, whereas the echo detection receiving power rapidly decreases to approximately 0 mW. Through systematic simulation, the study successfully explores the laser protection performance of the tangent phase mask wavefront coding imaging system, verifying its effectiveness.