We present a tabletop-scale spotlight-mode down-looking synthetic aperture imaging ladar (DL SAIL) demonstrator, which is performed by a collimator with 10 m focal length to simulate the far-field optical field. A specular-point target and a diffuse-reflection target have been used for resolution analysis and 2D imaging, respectively. The experimental result is in agreement with the theoretical design. The experiment setup is capable of simulating a real application scenario for further study. This Letter is focused on the proposition and implementation of spotlight-mode DL SAIL.

A second generation solar adaptive optics (AO) system is built and installed at the 1-m New Vacuum Solar Telescope (NVST) of the Fuxian Solar Observatory (FSO) in 2015. The AO high-order correction system consists of a 151-element deformable mirror (DM), a correlating Shack–Hartmann (SH) wavefront sensor (WFS) with a 3500 Hz frame rate, and a real-time controller. The system saw first light on Mar. 16, 2015. The simultaneous high-resolution photosphere and chromosphere images with AO are obtained. The on-sky observational results show that the contrast and resolution of the images are apparently improved after the wavefront correction by AO.