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Dou, X. (author), Zhou, Jiakang (author), Zhang, Yuquan (author), Min, Changjun (author), Pereira, S.F. (author), Yuan, Xiaocong (author)Optical singularities indicate zero-intensity points in space where parameters, such as phase, polarization, are undetermined. Vortex beams such as the Laguerre–Gaussian modes are characterized by a phase factor e<sup>il</sup><sup>θ</sup>, and contain a phase singularity in the middle of its beam. In the case of a transversal optical...journal article 2023
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Dou, X. (author), Min, Changjun (author), Zhang, Yuquan (author), Pereira, S.F. (author), Yuan, Xiaocong (author)Accurate determination of the physical parameters of nanostructures from optical far-field scattering is an important and challenging topic in the semiconductor industry. Here, we propose a novel metrology method to determine simultaneously the height and side-wall angle of a step-shaped silicon nanostructure. By employing an optical singular...journal article 2022
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Dou, X. (author), Pereira, S.F. (author), Min, Changjun (author), Zhang, Yuquan (author), Meng, P. (author), Urbach, Paul (author), Yuan, Xiaocong (author)The sidewall angle (SWA) of a nanostructure exerts influence on the performance of the nanostructure and plays an important role in processing nano-structural chips. It is still a great challenge to determine steep SWAs from far field measurements especially when the SWAs are close to 90°. Here, we propose a far-field detection system to...journal article 2021