The current application of domestic grating design software has long been dependent on commercial solutions such as VirtualLab and Gsolver. This reliance restricts the autonomy and innovation in the design of grating, metasurfaces, and microstructures. To meet the requirements of their design and analysis, there is an imperative need to fill the gap with domestic grating design software. The Grating Designer software, developed by Chinese researchers, not only satisfies the diverse requirements of grating and microstructure design, which ranges from modeling to analysis and optimization, but also has the ability to accelerate optimization and iterative convergence in the process of grating design.

The development of Grating Designer involves a comprehensive exploration of the Fourier modal method (FMM), also known as rigorous coupled wave analysis (RCWA), supported by thin element approximation, Gaussian elimination, matrix eigenvalue and eigenvector solving, matrix inversion, and other solution methods. The FMM serves as the analytical core, rigorously solving Maxwell equations within the periodic region of the grating. This method transforms the solution of Maxwell equations into determination of eigenvalues and eigenvectors. It applies them to the boundary conditions of the grating and substrate or medium regions, ultimately yielding results such as optical field, phase, and diffraction order. The software offers functionalities including construction, visualization, diffraction angle calculation, order calculation, diffraction efficiency analysis, reflection calculation, internal field calculation, transmission field calculation, and parameter scanning for 16 types of one-dimensional gratings and their derived two-dimensional gratings. The software development, driven by practical grating design and analysis requirements, features user-friendly tabular parameter input, simultaneous multi-parameter scan, and efficient parallel processing capabilities. Compared with mainstream grating design software, Grating Designer has a completely independent core code, supporting analysis of a wider range of grating types, including one- and two-dimensional gratings, microstructures, and metasurfaces, while facilitating the convenient addition of cladding layers, inner layers, outer layers, and other structures. The software diffraction efficiency and field distribution calculation results are consistent with those of mainstream design software such as VirtualLab and Gsolver.

The domestically developed software Grating Designer is innovative owing to its status as a completely independent software with a fully controllable core code. This independence provides it with a high degree of reliability and the agility to adapt and evolve according to user needs. Grating Designer innovative use of tabular parameter input, and features such as one-click selection, one-click display of grating morphology, and grating design cases considerably facilitate the construction of complex grating structures. User-friendly interface allows users to manipulate parameters such as duty cycle and modulation depth, as well as the addition of cladding layers and inner/outer membrane layers with ease (Fig.5). Grating Designer excels by introducing a feature that allows for the simultaneous scanning of multiple parameters (Fig.12), making it an all-encompassing solution for grating design and optimization. This multifaceted capability ensures that grating designs are both precise and adaptable to real-world conditions. Unlike VirtualLab and Gsolver softwares, Grating Designer encompasses various pre-set grating structures and design cases, allowing for arbitrary changes to the geometric parameters when constructing grating sawtooth structures, thus enhancing the flexibility of one-dimensional grating design. All one-dimensional grating morphologies constructed by Grating Designer can be transformed into novel two-dimensional grating morphologies through symmetric rotation and translation, high-low cross translation, and coordinate plane transformation (Fig.8), significantly expanding the design scope of two-dimensional gratings and microstructures. Grating Designer supports the calculation of electromagnetic waves from extreme ultraviolet to terahertz bands, and under a broader wavelength range, Grating Designer supports the use of conductivity to define materials. This feature expands its range of applications beyond grating design and analysis to accommodate metallic metasurfaces, antennas, and other design and analysis applications. Considering the complexity of grating construction in Grating Designer, the software employs multi-threaded parallel algorithms to achieve efficient parallel computing, as evidenced from tests on highly complex two-dimensional microstructures constructed within Grating Designer.

This paper presents the development and features of Grating Designer, a fully independent software with computational capabilities and precision in diffraction order, diffraction efficiency, and field distribution comparable to those of mainstream international grating design software. Additionally, Grating Designer possesses a more extensive capability for one- and two-dimensional grating construction, facilitating efficient design and analysis across a broader wavelength range for a wider range of grating, metasurfaces, and microstructures. Grating Designer represents a novel software development in domestic grating design, and its computational accuracy and range of applications will continue to be optimized.