Designing a sparse array with reduced transmit/receive modules(TRMs)is vital for some applications where the antenna system’s size,weight,allowed operating space,and cost are limited.Sparse arrays exhibit distinct ar...Designing a sparse array with reduced transmit/receive modules(TRMs)is vital for some applications where the antenna system’s size,weight,allowed operating space,and cost are limited.Sparse arrays exhibit distinct architectures,roughly classified into three categories:Thinned arrays,nonuniformly spaced arrays,and clustered arrays.While numerous advanced synthesis methods have been presented for the three types of sparse arrays in recent years,a comprehensive review of the latest development in sparse array synthesis is lacking.This work aims to fill this gap by thoroughly summarizing these techniques.The study includes synthesis examples to facilitate a comparative analysis of different techniques in terms of both accuracy and efficiency.Thus,this review is intended to assist researchers and engineers in related fields,offering a clear understanding of the development and distinctions among sparse array synthesis techniques.展开更多
Noble metallic nanostructures with strong electric near-field enhancement can significantly improve nanoscale light-matter interactions and are critical for high-sensitivity surface-enhanced Raman spectroscopy[SERS].H...Noble metallic nanostructures with strong electric near-field enhancement can significantly improve nanoscale light-matter interactions and are critical for high-sensitivity surface-enhanced Raman spectroscopy[SERS].Here,we use an azimuthal vector beam[AVB]to illuminate the plasmonic tips circular cluster[PTCC]array to enhance the electric near-field intensity of the PTCC array,and then use it to improve SERS sensitivity.The PTCC array was prepared based on the self-assembled and inductive coupled plasmon[ICP]etching methods.The calculation results show that,compared with the linearly polarized beam[LPB]and radial vector beam excitations,the AVB excitation can obtain stronger electric near-field enhancement due to the strong resonant responses formed in the nanogap between adjacent plasmonic tips.Subsequently,our experimental results proved that AVB excitation increased SERS sensitivity to 10-13mol/L,which is two orders of magnitude higher than that of LPB excitation.Meanwhile,the PTCC array had excellent uniformity with the Raman enhancement factor calculated to be~2.4×10^[8].This kind of vector light field enhancing Raman spectroscopy may be applied in the field of sensing technologies,such as the trace amount detection.展开更多
基金supported by the National Natural Science Foundation of China under Grant No.U2341208.
文摘Designing a sparse array with reduced transmit/receive modules(TRMs)is vital for some applications where the antenna system’s size,weight,allowed operating space,and cost are limited.Sparse arrays exhibit distinct architectures,roughly classified into three categories:Thinned arrays,nonuniformly spaced arrays,and clustered arrays.While numerous advanced synthesis methods have been presented for the three types of sparse arrays in recent years,a comprehensive review of the latest development in sparse array synthesis is lacking.This work aims to fill this gap by thoroughly summarizing these techniques.The study includes synthesis examples to facilitate a comparative analysis of different techniques in terms of both accuracy and efficiency.Thus,this review is intended to assist researchers and engineers in related fields,offering a clear understanding of the development and distinctions among sparse array synthesis techniques.
基金supported by the National Natural Science Foundation of China(NSFC)(Nos.11974282 and 91950207)the Doctoral Dissertation Innovation Fund of Northwestern Polytechnical University(No.CX2021039)。
文摘Noble metallic nanostructures with strong electric near-field enhancement can significantly improve nanoscale light-matter interactions and are critical for high-sensitivity surface-enhanced Raman spectroscopy[SERS].Here,we use an azimuthal vector beam[AVB]to illuminate the plasmonic tips circular cluster[PTCC]array to enhance the electric near-field intensity of the PTCC array,and then use it to improve SERS sensitivity.The PTCC array was prepared based on the self-assembled and inductive coupled plasmon[ICP]etching methods.The calculation results show that,compared with the linearly polarized beam[LPB]and radial vector beam excitations,the AVB excitation can obtain stronger electric near-field enhancement due to the strong resonant responses formed in the nanogap between adjacent plasmonic tips.Subsequently,our experimental results proved that AVB excitation increased SERS sensitivity to 10-13mol/L,which is two orders of magnitude higher than that of LPB excitation.Meanwhile,the PTCC array had excellent uniformity with the Raman enhancement factor calculated to be~2.4×10^[8].This kind of vector light field enhancing Raman spectroscopy may be applied in the field of sensing technologies,such as the trace amount detection.
