Fig. 5: Grating profile evolution with 4 wt.‰ NaOH solution.
From: 400nm ultra-broadband gratings for near-single-cycle 100 Petawatt lasers
a Measured diffraction efficiencies of samples in Round I at 750–1150 nm. b–e Grating groove profile measured by AFM and FIB-SEM. The curves are labeled according to developer concentration, developing time, and sample number. f Structure parameter inversion for S1–S4. The error bar stands for the statistical error.
