Fig. 4
From: Dynamic beam steering with all-dielectric electro-optic III–V multiple-quantum-well metasurfaces
Demonstration of switchable diffraction grating. a Schematic of the dynamic diffraction grating, which can be realized by changing the grating periodicity via an appropriate bias application. b SEM image of the fabricated sample, which we used for the demonstration of the dynamic beam switching. c Optical setup for far-field radiation pattern measurements. M: mirror, ND: neutral density filter, I: iris, BS: beam splitter, O: objective with 0.28 numerical aperture, L: lens. d Experimentally measured intensity of the scattered light in the far-field as a function of diffraction angle and applied voltage. The first-order diffracted beam appears when the applied voltage is lower than −3 V. The plotted diffracted light intensity is normalized to the light intensity at 0°. The light intensity is plotted for a wavelength of 917 nm. e Intensity of the scattered light as a function of the diffraction angle at an applied bias of 0 V (top panel) and at an applied bias of −10 V (bottom panel). The ±1 diffraction order clearly appears when the applied voltage is decreased to −10 V
