Comparative analysis for different designs of two-dimensional binary sinusoidal transmission gratings

Diffraction gratings serve as a suitable optical element for spectral analysis, as light is spatially separated by its constituting wavelengths. Unlike conventional bar gratings that produce many high-diffraction orders, sinusoidal gratings enable suppression of the high orders, leaving only the first order. This makes the sinusoidal grating a promising candidate for spectral analysis for a wide range of wavelengths. Here, we provide a comparative analysis both theoretically and experimentally of two different two-dimensional binary amplitude sinusoidal gratings for high-order suppression. The grating efficiency and the corresponding spectral resolutions are calculated. The two nanofabricated gratings provide accurate experimental spectrum with high correlation between measurements.