Extended-range digital holographic imaging

Abstract

We report the results of experiments demonstrating large-format coherent imaging at a range of 1.5 km. For this work, we use digital holographic detection to record coherent data and are thus able to measure the complex-valued optical field from a flood-illuminated scene over an extended aperture. Images are formed using digital Fourier processing. The return light is interfered with a coherent reference beam, and the intensity of the interference pattern is recorded using a conventional large-format detector array. Experimental results obtained using a coherent, pulsed laser source operating at 1.6 microns are presented. We also demonstrate the utility of this technique for advanced imaging functions such as 3D imaging.