micromachines-11-00521 (1).pdf (643.05 kB)
Route to intelligent imaging reconstruction via terahertz nonlinear ghost imaging
Version 2 2023-06-07, 08:47
Version 1 2023-06-07, 07:04
journal contribution
posted on 2023-06-07, 08:47 authored by Juan Sebastian Totero Gongora, Luana OlivieriLuana Olivieri, Luke Peters, Jacob Tunesi, Vittorio Cecconi, Antonio CutronaAntonio Cutrona, Robyn Tucker, Vivek Kumar, Alessia Pasquazi, Marco PecciantiTerahertz (THz) imaging is a rapidly emerging field, thanks to many potential applications in diagnostics, manufacturing, medicine and material characterisation. However, the relatively coarse resolution stemming from the large wavelength limits the deployment of THz imaging in micro- and nano-technologies, keeping its potential benefits out-of-reach in many practical scenarios and devices. In this context, single-pixel techniques are a promising alternative to imaging arrays, in particular when targeting subwavelength resolutions. In this work, we discuss the key advantages and practical challenges in the implementation of time-resolved nonlinear ghost imaging (TIMING), an imaging technique combining nonlinear THz generation with time-resolved time-domain spectroscopy detection. We numerically demonstrate the high-resolution reconstruction of semi-transparent samples, and we show how the Walsh–Hadamard reconstruction scheme can be optimised to significantly reduce the reconstruction time. We also discuss how, in sharp contrast with traditional intensity-based ghost imaging, the field detection at the heart of TIMING enables high-fidelity image reconstruction via low numerical-aperture detection. Even more striking—and to the best of our knowledge, an issue never tackled before—the general concept of “resolution” of the imaging system as the “smallest feature discernible” appears to be not well suited to describing the fidelity limits of nonlinear ghost-imaging systems. Our results suggest that the drop in reconstruction accuracy stemming from non-ideal detection conditions is complex and not driven by the attenuation of high-frequency spatial components (i.e., blurring) as in standard imaging. On the technological side, we further show how achieving efficient optical-to-terahertz conversion in extremely short propagation lengths is crucial regarding imaging performance, and we propose low-bandgap semiconductors as a practical framework to obtain THz emission from quasi-2D structures, i.e., structure in which the interaction occurs on a deeply subwavelength scale. Our results establish a comprehensive theoretical and experimental framework for the development of a new generation of terahertz hyperspectral imaging devices.
Funding
TIMING - Time-Resolved Nonlinear Ghost Imaging; G2016; EUROPEAN UNION; 725046
History
Publication status
- Published
File Version
- Published version
Journal
MicromachinesISSN
2072-666XPublisher
MDPIExternal DOI
Issue
5Volume
11Article number
a521Department affiliated with
- Physics and Astronomy Publications
Full text available
- No
Peer reviewed?
- Yes
Legacy Posted Date
2020-05-22First Open Access (FOA) Date
2020-05-22First Compliant Deposit (FCD) Date
2020-05-21Usage metrics
Categories
No categories selectedKeywords
Licence
Exports
RefWorks
BibTeX
Ref. manager
Endnote
DataCite
NLM
DC