• Fast Fourier transport analysis of surface structures fabricated by laser interference lithography

      Liu, Mengnan; Dong, Litong; Zhang, Ziang; Li, Li; Wang, Lu; Song, Zhengxun; Weng, Zhankun; Han, Xueyan; Zhou, Linhua; Wang, Zuobin (The Japan Society of Applied Physics, 2019-08-14)
      This paper presents an FFT (fast Fourier transform) analytical method for the study of surface structures fabricated by laser interference lithography (LIL). In the work, the FFT analytical method combined with Gaussian fitting is used to determine the periods and pattern distributions of surface structures from frequency spectra. For LIL, the processing parameters of incident and azimuth angles can be obtained corresponding to the period and pattern distribution. This work facilitates the detection of micro- and nano-structures, the analysis of pattern distribution in engineering, and the processing error analysis of LIL.
    • Superlens-enhanced laser interference lithography

      Guo, Xudong; Li, Li; Hu, Yaowei; Cao, Liang; Dong, Litong; Wang, Lu; Ding, Ran; Weng, Zhankun; Song, Zhengxun; Xu, Hongmei; et al. (IOP Publishing, 2018-11-14)
      A one-step lithography method based on a superlens is proposed to fabricate diffraction-unlimited metallic patterns. By controlling the material parameters and the distribution of the impinging energy, various phenomena, such as periodic nanonetworks, ultrathin nanowires (sub-50-nm feature size), and variable-sized nanoparticles (ranging from sub-10nm to several hundreds of nanometers), are fabricated using a 1,064-nm nanosecond laser. The evolution pathway of such phenomena is explained by the dewetting process of metallic films. The direct-writing performance of a transparent material with a superlens is studied, and the maximum etching depth of Si gratings can reach 2 μm under a single laser pulse, with fine profiles. © 2018 The Japan Society of Applied Physics