Synthetic aperture radar can measure the phase of a microwave with an antenna, which cannot be directly extended to visible light imaging due to phase lost. In this Letter, we report an active remote sensing with visible light via reflective Fourier ptychography, termed coherent syn-thetic aperture imaging (CSAI), achieving high resolution, a wide field-of-view (FOV), and phase recovery. A proof-of-concept experiment is reported with laser scanning and a collimator for the infinite object. Both smooth and rough objects are tested, and the spatial resolution increased from 15.6 to 3.48μm with a factor of 4.5.The speckle noise can be suppressed obviously, which is important for coherent imaging. Meanwhile, the CSAI method can tackle the aberration induced from the optical system by one-step deconvolution and shows the potential to replace the adaptive optics for aberration removal of atmospheric turbulence.
(a) Scenario of the CSAI system. (a1) Close-up of the imaging system. (b) and (c) Effective FOV of the camera scanning and the laser scanning schemes. (d) Simplified CSAI setup. (e) Photograph of the CSAI system. (f) Close-up of the laser module for illumination. (g)Close-up of the camera for image acquisition.
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