Fig. 3. Demonstration of space gating in confocal imaging.

Images were reconstructed by scanning 900 points within a 16.1 × 16.1 µm² field of view. a–d Reconstructed intensity images of 2-μm gold-coated microspheres without space gating when the optical thicknesses of the input and output layers were (0, 0), (6.9, 10.6), (6.9, 12.8), and (10.6, 12.8), respectively. e–h Reconstructed images with space gating for the same configurations as a–d. Images were normalized to their maximum intensities. Scale bar: 2 µm.