Wide-waveband and wide-angle blazing meta-fringe grating with global structural and angular dispersion engineering

Diffraction gratings are the core elements in fields such as dispersion control and spectral detection. Traditional gratings can achieve maximum constructive interference and maximum period diffraction simultaneously for a single wavelength with a certain angle of incidence to meet the Bragg or blazing condition. Here, we expand the applicability of the blazing condition and propose a theory and its design scheme for meta-fringe gratings with a wide blazing waveband and a wide range of blazing angle of incidence. Based on global 2-dimensional control with structural dispersion and angle dispersion engineering, we enable meta-fringe gratings to exhibit simultaneous blazing across all wavelengths within the visible band over a wide range of incident angles. The design achieves an average diffraction efficiency exceeding 90% for wavelengths from 450 nm to 650 nm within an incident angle range of ±15°. The design theory and its scheme allow meta-fringe gratings to move beyond the limitations of traditional Littrow or blazing configurations, enabling flexible use of angle of incidence while achieving high diffraction efficiency across a broadband. It enriches the theoretical framework for metasurface grating design and significantly expands the application of metasurface gratings.