Control of visible‑range transmission and refection haze by varying pattern size,shape and depth in fexible metasurfaces  

作　　者：Avijit Maity Vaswati Biswas R.Vijaya 

机构地区：[1]Department of Physics,Indian Institute of Technology Kanpur,Kanpur 208016,India [2]Centre for Lasers and Photonics,Indian Institute of Technology Kanpur,Kanpur 208016,India

出　　处：《Frontiers of Optoelectronics》2024年第3期51-68,共18页光电子前沿（英文版）

基　　金：DST,India,under the India-Taiwan S&T co-operation project(GITA/DST/TWN/P-61/2014);IRDE Dehradun,India,under the DRDO Nanophotonics program(ST-12/IRD-124).

摘　　要：Cost-efective soft imprint lithography technique is used to prepare fexible thin polymeric surfaces containing a periodic arrangement of nanodimples and nanobumps of sub-micron size.Using a single master mold of self-assembled colloidal crystal,metasurfaces with diferent depths and heights of patterns with a fxed pitch are possible,which makes the process inexpensive and simple.These metasurfaces are studied for their difuse and total transmission and refection spectra in the visible range.The transmission haze and refection haze are calculated from the measurements.The surface containing nanobumps of lesser pattern height result in higher values of refection and transmission haze than from surfaces containing nanodimples of much higher depth for the same pitch.The haze is more dependent on the pattern depth or height and less dependent on the pitch of the pattern.Far-feld transmission profles measured in the same wavelength range from the patterned surfaces show that the scattering increases with the increase of the ratio of pattern depth/height to pitch,similar to the haze measurements conducted with a closed integrating sphere.These profles show that the angular spread of scattered light in transmission is within 10°,explaining the reason for the relatively low transmission haze in all the patterned surfaces.Simulation results confrm that the nanobump pattern gives higher transmission haze compared to nanodimple pattern.By controlling the ratio of pattern depth/height to pitch of the features on these surfaces,both an increase in optical haze and a balance between total refection intensity and total transmission intensity can be achieved.

关 键 词：Metasurface Refection haze Transmission haze Soft imprint lithography 

分 类 号：TQ317[化学工程—高聚物工业] O441.4[理学—电磁学]