Multi-Wavelength Spot-Array Beams Based on Tunable Dammann Grating Metasurface

The structured light projection (SLP) method occupies a crucial position in three-dimensional (3D) imaging technology. Different working wavelengths of can be employed depending on the situation. However, there are few lights that modulated based wavelength at present. Therefore, we have comprehensively investigated and designed Dammann grating (DG) metasurface, which controlled through multi-beam interference (MBI) to achieve change wavelength. In this work, convert straight waveguide helical by fine-tuning related parameters incident generate 5 × diffraction spot arrays range 480–510 nm 950–1020 nm, respectively. Furthermore, metasurfaces exhibit good performance. For example, their spread angles up 44° they reach conversion efficiency over ?50% while maintaining contrast ratio roughly 40%. Compared with traditional light, it used different has broader application 3D sensing systems.