Holographic lithography of one-dimensional subwavelength infrared polarization gratings
Subwavelength gratings,as compact,easily integrable polarization-selective devices with high extinction ratios,hold significant potential for applications in remote sensing,material stress detection,an-ti-scattering imaging,and related fields,garnering widespread attention.In this study,we design a one-di-mensional subwavelength grating polarization-selective device with high extinction ratios and high transmit-tance,along with an efficient fabrication method.Utilizing the effective medium theory and finite-differ-ence time-domain simulations,we developed and modeled a one-dimensional subwavelength grating de-vice featuring a double-layer metal structure optimized for holographic interference processing.This design offers robust duty cycle tolerance and facilitates the direct transfer of photoresist patterns.A holographic la-ser lithography system was constructed to fabricate one-dimensional gratings with dimensions of 30 mm×30 mm and a period of 800 nm.Compared to conventional techniques,this approach demonstrates signifi-cant advantages in processing efficiency,cost-effectiveness,and tunable periodicity.The transfer of photo-resist patterns to metal gratings was achieved via silicon substrate etching and metal film deposition.The resulting gratings exhibit an average transmittance exceeding 45%and a maximum extinction ratio of 30 dB for infrared wavelengths in the range of 3-15 μm.
hololithographydouble-layer metal gratinsubwavelength gratingpolarization selection
万方数据
维普
