posted on 2023-06-09, 20:21authored byLuana OlivieriLuana Olivieri, Juan Sebastian Totero Gongora, Luke Peters, Vittorio Cecconi, Antonio Cutrona, Jacob Tunesi, Robyn Tucker, Alessia Pasquazi, Marco Peccianti
Ghost-imaging, based on single-pixel detection and multiple pattern illumination, is a crucial investigation tool in difficult-to-access wavelength regions. In the terahertz domain, where high-resolution imagers are mostly unavailable, Ghost-imaging is an optimal approach to embed the temporal dimension, creating a ‘hyperspectral’ imager. In this framework high-resolution is mostly out-of-reach. Hence, it is particularly critical to developing practical approaches for microscopy. Here we experimentally demonstrate Time-Resolved Nonlinear Ghost-Imaging, a technique based on near-field, optical-to-terahertz nonlinear conversion and detection of illumination patterns. We show how space-time coupling affects near-field time-domain imaging and we develop a complete methodology that overcomes fundamental systematic reconstruction issues. Our theoretical-experimental platform enables high-fidelity subwavelength imaging and carries relaxed constrains on the nonlinear generation crystal thickness. Our work establishes a rigorous framework to reconstruct hyperspectral images of complex samples inaccessible through standard fixed-time methods.