Thickness Detection Based on the Wavelength- and Angle-Interrogation of Surface Lattice Resonance

This paper reports an ultrathin film thickness detection method based on the transverse electric (TE) mode surface lattice resonance (SLR) in an all-metal metasurface. The Ab03 thickness can be characterized precisely by wavelength redshifts or resonance angle increments, respectively. The wavelength-interrogation detection limit and sensitivity are 5 nm and 2.16 nm/nm. This angle-interrogation adopts TE SLR mechanism and improved measurement. The angle sensitivity reaches 2.10 ° /nm larger than that of surface plasmon polariton (SPP) over one magnitude. This research paves a momentous step towards multiple channel detection of nanoscale thickness.