Off‐axis self‐reference digital holography in the visible and far‐infrared region

Abstract

Recent advances in digital holography in the far‐infrared region of the spectrum have demonstrated the potential use of digital holography in homeland security as a tool to observe hostile environments in which smoke, flames, and dust impair vision. However, to make this application practical, it is necessary to simplify the optical setup. Here, we show an off‐axis, self‐reference scheme that spills the reference beam out from the object beam itself and avoids the need for a complex interferometric arrangement. We demonstrate that this scheme allows the reconstruction of high‐quality holograms of objects captured under visible as well as far‐infrared light exposure. This could pave the way to the industrialization of holographic systems to enable users to see through fire. Moreover, the quantitative nature of the holographic signal is preserved. Thus, the reported results demonstrate the possibility to use this setup for optical metrology.

Free Field of View Infrared Digital Holography for Mineral Crystallization

“…Numerous researchers have delved into IDH, exploring multiple wavelengths and applications. One such application involves the use of a 10.6 μm laser for imaging in smoke and flames, aiding in fire rescue research. − Additionally, IDH enables real-time remote monitoring of building vibration patterns and facilitates research in view scanning reconstruction . Various algorithms are investigated, including the elimination of holographic zero-level diffraction, noise suppression, and autofocus. − Incoherent imaging in the mid-infrared range is based on the Lucy–Richardson–Rosen method .…”