Fig. 3: The performance of rewritiable WO3-based gratings.
From: Spatially-resolved insulator-metal transition for rewritable optical gratings
a Photoresist is covered on a WO3 film as the shape of “USTC”, which proves that photoresist would hinder the electron–proton synergistic doping. b The synergistic effect is compatible with UV lithography, which can be conducted in microchannels by coating photoresist. c-f The photos recorded by optical microscope: a photoresist array in bar shape (c) and a photoresist array in square shape (d). After being processed by synergistic doping and lift-off, the corresponding pattern of bars (e) and squares (f) were obtained. Panels c–f have the same scale bar. The period is 16 μm. g–j The corresponding surface morphology of samples in panels c–f. k–n The corresponding diffraction spots of samples in panels c–f. For panels k–n, scale bar is the same. o The WO3 relief grating in the period of 16 μm, p surface morphology, t diffraction spots. q–s Adjusting the period of the relief grating by the synergistic doping, 32 μm for panel q, 64 μm for panel r, 64 μm for panel s. u–w The corresponding diffraction spots of samples in panels q–s. For panels o and q–s, scale bar is the same. For panels t–w, scale bar is the same.
