Terahertz nonlinear ghost imaging via plane decomposition: Towards near-field micro-volumetry: Fig.2. US temporal movie

 Terahertz time-domain imaging targets the reconstruction of the full electromagnetic morphology of an object. In this spectral range, the near-field propagation strongly affects the information in the space-time domain in items with microscopic features. While this often represents a challenge, as the information needs to be disentangled to obtain high image fidelity, here we show that such a phenomenon can enable three-dimensional microscopy. Specifically, we investigate the capability of the time-resolved nonlinear ghost imaging (TNGI) methodology to implement field-sensitive micro-volumetry by plane decomposition. We leverage the temporally-resolved, field-sensitive detection to ‘refocus’ an image plane at an arbitrary distance from the source, which defines the near-field condition, and within a microscopic sample. Since space-time coupling rapidly evolves and diffuses within subwavelength length scales, our technique can separate and discriminate the information originating from different planes at different depths. Our approach is particularly suitable for objects with sparse micrometric details. Building upon this principle, we demonstrate complex, time-domain volumetry resolving internal object planes with sub-wavelength resolution, discussing the range of applicability of our technique. </p

Concurrent terahertz generation via quantum interference in a quadratic media

The strive for efficiency in the generation of terahertz (THz) waves motivates intense research on novel field–matter interactions. Presently, THz generation via quadratic crystals remains the benchmark thanks to its simple and practical deployment. An interesting problem is whether new mechanisms can be exploited to elicit novel generation approaches and forms of control on the THz output in existing systems. THz generation via quantum interference (QI) leverages a third-order nonlinear response under resonant absorption, and it has been recently explored to access surface generation in centrosymmetric systems. Its deployment in standard THz quadratic sources can potentially create a physical setting with the concurrence of two different mechanisms. Here, THz generation via QI in noncentrosymmetric crystals concurrent with phase-matched quadratic generation in a bulk-transmission setting is demonstrated. Beyond investigating a new physical setting, it is demonstrated that conversion efficiencies much larger than those typically associated with the medium become accessible for a typically adopted crystal, ZnTe. An inherent control on the relative amplitude and sign of the two generated THz components is also achieved. This approach provides disruptive boost and management of the optical-to-THz conversion performance of a well-established technology, with significant ramifications in emerging spectroscopy and imaging applications. </p

Dataset for Concurrent terahertz generation via quantum interference in a quadratic media

Dataset to accompany the paper    "Concurrent terahertz generation via quantum interference in a quadratic media." The dataset is provided in a .fig format which contains the figures for the paper. The file format also contains the datasets for each of the figures.</p

Terahertz nonlinear ghost imaging via plane decomposition: Towards near-field micro-volumetry: Fig.2. US spectral movie

 Terahertz time-domain imaging targets the reconstruction of the full electromagnetic morphology of an object. In this spectral range, the near-field propagation strongly affects the information in the space-time domain in items with microscopic features. While this often represents a challenge, as the information needs to be disentangled to obtain high image fidelity, here we show that such a phenomenon can enable three-dimensional microscopy. Specifically, we investigate the capability of the time-resolved nonlinear ghost imaging (TNGI) methodology to implement field-sensitive micro-volumetry by plane decomposition. We leverage the temporally-resolved, field-sensitive detection to ‘refocus’ an image plane at an arbitrary distance from the source, which defines the near-field condition, and within a microscopic sample. Since space-time coupling rapidly evolves and diffuses within subwavelength length scales, our technique can separate and discriminate the information originating from different planes at different depths. Our approach is particularly suitable for objects with sparse micrometric details. Building upon this principle, we demonstrate complex, time-domain volumetry resolving internal object planes with sub-wavelength resolution, discussing the range of applicability of our technique. </p

Terahertz nonlinear ghost imaging via plane decomposition: Towards near-field micro-volumetry: Fig.3. MGI spectral movie

Terahertz time-domain imaging targets the reconstruction of the full electromagnetic morphology of an object. In this spectral range, the near-field propagation strongly affects the information in the space-time domain in items with microscopic features. While this often represents a challenge, as the information needs to be disentangled to obtain high image fidelity, here we show that such a phenomenon can enable three-dimensional microscopy. Specifically, we investigate the capability of the time-resolved nonlinear ghost imaging (TNGI) methodology to implement field-sensitive micro-volumetry by plane decomposition. We leverage the temporally-resolved, field-sensitive detection to ‘refocus’ an image plane at an arbitrary distance from the source, which defines the near-field condition, and within a microscopic sample. Since space-time coupling rapidly evolves and diffuses within subwavelength length scales, our technique can separate and discriminate the information originating from different planes at different depths. Our approach is particularly suitable for objects with sparse micrometric details. Building upon this principle, we demonstrate complex, time-domain volumetry resolving internal object planes with sub-wavelength resolution, discussing the range of applicability of our technique. </p

Terahertz nonlinear ghost imaging via plane decomposition: Towards near-field micro-volumetry: Fig.3. MGI temporal movie

Terahertz time-domain imaging targets the reconstruction of the full electromagnetic morphology of an object. In this spectral range, the near-field propagation strongly affects the information in the space-time domain in items with microscopic features. While this often represents a challenge, as the information needs to be disentangled to obtain high image fidelity, here we show that such a phenomenon can enable three-dimensional microscopy. Specifically, we investigate the capability of the time-resolved nonlinear ghost imaging (TNGI) methodology to implement field-sensitive micro-volumetry by plane decomposition. We leverage the temporally-resolved, field-sensitive detection to ‘refocus’ an image plane at an arbitrary distance from the source, which defines the near-field condition, and within a microscopic sample. Since space-time coupling rapidly evolves and diffuses within subwavelength length scales, our technique can separate and discriminate the information originating from different planes at different depths. Our approach is particularly suitable for objects with sparse micrometric details. Building upon this principle, we demonstrate complex, time-domain volumetry resolving internal object planes with sub-wavelength resolution, discussing the range of applicability of our technique. </p

Terahertz nonlinear ghost imaging via plane decomposition: Towards near-field micro-volumetry: Supplementary information

Terahertz time-domain imaging targets the reconstruction of the full electromagnetic morphology of an object. In this spectral range, the near-field propagation strongly affects the information in the space-time domain in items with microscopic features. While this often represents a challenge, as the information needs to be disentangled to obtain high image fidelity, here we show that such a phenomenon can enable three-dimensional microscopy. Specifically, we investigate the capability of the time-resolved nonlinear ghost imaging (TNGI) methodology to implement field-sensitive micro-volumetry by plane decomposition. We leverage the temporally-resolved, field-sensitive detection to ‘refocus’ an image plane at an arbitrary distance from the source, which defines the near-field condition, and within a microscopic sample. Since space-time coupling rapidly evolves and diffuses within subwavelength length scales, our technique can separate and discriminate the information originating from different planes at different depths. Our approach is particularly suitable for objects with sparse micrometric details. Building upon this principle, we demonstrate complex, time-domain volumetry resolving internal object planes with sub-wavelength resolution, discussing the range of applicability of our technique. </p

Terahertz nonlinear ghost imaging via plane decomposition: Towards near-field micro-volumetry: Dataset for the article

This is the dataset for the article "Terahertz  Nonlinear Ghost Imaging via Plane Decomposition: Towards Near-Field Micro-Volumetry". The data is saved in their respective folders, in the Matlab format .fig .</p

Terahertz nonlinear ghost imaging via plane decomposition: Towards near-field micro-volumetry

Terahertz time-domain imaging targets the reconstruction of the full electromagnetic morphology of an object. In this spectral range, the near-field propagation strongly affects the information in the space-time domain in items with microscopic features. While this often represents a challenge, as the information needs to be disentangled to obtain high image fidelity, here we show that such a phenomenon can enable three-dimensional microscopy. Specifically, we investigate the capability of the time-resolved nonlinear ghost imaging (TNGI) methodology to implement field-sensitive micro-volumetry by plane decomposition. We leverage the temporally-resolved, field-sensitive detection to ‘refocus’ an image plane at an arbitrary distance from the source, which defines the near-field condition, and within a microscopic sample. Since space-time coupling rapidly evolves and diffuses within subwavelength length scales, our technique can separate and discriminate the information originating from different planes at different depths. Our approach is particularly suitable for objects with sparse micrometric details. Building upon this principle, we demonstrate complex, time-domain volumetry resolving internal object planes with sub-wavelength resolution, discussing the range of applicability of our technique.</p

Terahertz spatiotemporal wave synthesis in random systems

Complex media have emerged as a powerful and robust framework to control light–matter interactions designed for task-specific optical functionalities. Studies on wavefront shaping through disordered systems have demonstrated optical wave manipulation capabilities beyond conventional optics, including aberration-free and subwavelength focusing. However, achieving arbitrary and simultaneous control over the spatial and temporal features of light remains challenging. In particular, no practical solution exists for field-level arbitrary spatiotemporal control of wave packets. A new paradigm shift has emerged in the terahertz frequency domain, offering methods for absolute time-domain measurements of the scattered electric field, enabling direct field-based wave synthesis. In this work, we report the experimental demonstration of field-level control of single-cycle terahertz pulses on arbitrary spatial points through complex disordered media.</p