Dual-beam interference lithography is a core technology for two-dimensional(2D)grating fabrication.However,significant morphological deviations occur between the fabricated structures and traditional theoretical model...Dual-beam interference lithography is a core technology for two-dimensional(2D)grating fabrication.However,significant morphological deviations occur between the fabricated structures and traditional theoretical models,causing diffraction efficiency prediction discrepancies.To address this issue,this paper proposes a hole–pillar coupled design model for 2D gratings fabricated via dual-beam interference lithography.By constructing the actual three-dimensional(3D)grating morphology,the proposed model describes the grating profile evolution during fabrication accurately.Using an inverse grating design method based on the Fourier modal method,a polarization-independent 2D grating structure with high diffraction efficiency was optimized for a 670 nm working wavelength.A 2D grating with a line density of 1200 gr/mm was fabricated using dual-beam interference lithography.Experimental results show that,when transverse electric/transverse magnetic-polarized light at 670 nm is perpendicularly incident,the diffraction efficiency of the(±1,0)and(0,±1)orders exceeds 20%,with a polarization imbalance of less than 3%.Atomic force microscopy characterization reveals a correlation coefficient of 0.988 between the actual and designed grating structures,verifying the proposed model's accuracy.The model provides a precise description of the groove profile in 2D holographic gratings,expands the grating fabrication tolerance,and provides a theoretical foundation for the development of next-generation nanoscale-precision multi-degree-of-freedom measurement systems.展开更多
基金Youth Innovation Promotion Association of the Chinese Academy of Sciences(2022218)Strategic Priority Research Program of the Chinese Academy of Sciences(XDC0280101)+3 种基金National Natural Science Foundation of China(62435019)CAS Project for Young Scientists in Basic Research(YSBR-103)National Key Research and Development Program of China(2023YFF0715802)Jilin Province and Chinese Academy of Sciences Science and Technology Cooperation High-Tech Industrialization Special Program(2024SYHZ0018)。
文摘Dual-beam interference lithography is a core technology for two-dimensional(2D)grating fabrication.However,significant morphological deviations occur between the fabricated structures and traditional theoretical models,causing diffraction efficiency prediction discrepancies.To address this issue,this paper proposes a hole–pillar coupled design model for 2D gratings fabricated via dual-beam interference lithography.By constructing the actual three-dimensional(3D)grating morphology,the proposed model describes the grating profile evolution during fabrication accurately.Using an inverse grating design method based on the Fourier modal method,a polarization-independent 2D grating structure with high diffraction efficiency was optimized for a 670 nm working wavelength.A 2D grating with a line density of 1200 gr/mm was fabricated using dual-beam interference lithography.Experimental results show that,when transverse electric/transverse magnetic-polarized light at 670 nm is perpendicularly incident,the diffraction efficiency of the(±1,0)and(0,±1)orders exceeds 20%,with a polarization imbalance of less than 3%.Atomic force microscopy characterization reveals a correlation coefficient of 0.988 between the actual and designed grating structures,verifying the proposed model's accuracy.The model provides a precise description of the groove profile in 2D holographic gratings,expands the grating fabrication tolerance,and provides a theoretical foundation for the development of next-generation nanoscale-precision multi-degree-of-freedom measurement systems.
