Fig. 2: Subdiffraction-limited images from GHOSTEAM.
a Optical image of an object with a field of view of FOV1 = 834 μm × 834 μm. The bright regions are gold attached on the 150-nm-thick protective SiO2 layer on top of the STEA. THz ghost images in FOV1 with a magnetic field (green arrows) applied along the vertical direction (b) and horizontal direction (c). The pixel size and scale bar are 13.0 μm and 100 μm, respectively, for both images. d THz ghost image in FOV2 (indicated by the black dashed box in a) with a pixel size of 6.5 μm and a scale bar of 50 μm. The applied magnetic field B is along the horizontal direction (indicated by the green arrow), and the polarization of the THz radiation (indicated by the white double-headed arrow) is perpendicular to B. e Averaged amplitude of the THz field along the black dashed arrow in (b). Blue dots are averaged experimental data, and the black solid curve is the fit to the Boltzmann sigmoidal function (see Supplementary section 5 for details). Grey areas represent the metal regions, with corresponding widths indicated. A contrast ratio of 57 ± 21% is observed at the 6-μm width metal slit.
