Near field

How to get image not limited by diffraction? Using near techniques of course!

To have a global overview about terahertz near field, you can look at this review.

In the paper presented below, you can see guided reflectometry and near field integrated resonators approaches.

Linear to radial polarization conversion in the THz domain using a passive system

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Terahertz research image associated with Continuous-wave scanning terahertz near-field microscope

The work presents a compact, passive device that transforms a conventional linearly polarized terahertz (THz) beam into a radially polarized one, a field configuration that offers superior focusing, enhanced longitudinal fields, and improved coupling to near‑field probes. By adapting a proven…

Continuous‐wave scanning terahertz near‐field microscope

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Terahertz research image associated with Continuous-wave scanning terahertz near-field microscope

The work reported by Guillet, Chusseau, Adam, Grosjean, Penarier, Baida and Charraut describes the development of a continuous‑wave terahertz (THz) near‑field microscope that exploits Sommerfeld surface waves guided along metallic wires. By combining differential phase plates, a Y‑splitter and a…

Near-field wire-based passive probe antenna for the selective detection of the longitudinal electric field at terahertz frequencies

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Terahertz research image associated with Continuous-wave scanning terahertz near-field microscope

The work presents a novel passive probe antenna that can be operated at terahertz (0.1 THz) frequencies using a simple, purely passive structure. The antenna consists of a slender metal wire backed by a discontinuous phase plate that converts an ordinary linearly‑polarized free‑space beam into a…

Coupling and Propagation of Sommerfeld Waves at 100 and 300 GHz

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Terahertz research image associated with Continuous-wave scanning terahertz near-field microscope

The study demonstrates that millimetre‑wave guided modes—known as Sommerfeld waves—can be efficiently launched and transported along simple metallic wires at 100 GHz and 300 GHz. By inserting a straightforward differential phase plate in front of the wire, the researchers achieved a theoretical…

Fast Terahertz Spectroscopic Holographic Assessment of Optical Properties of Diabetic Blood Plasma

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Terahertz research image associated with Fast terahertz spectroscopic holographic assessment of optical properties of diabetic blood plasma

The research presents a novel, rapid diagnostic technique that harnesses terahertz (THz) pulse time‑domain holography to evaluate the optical properties of lyophilized blood plasma pellets. By converting plasma into compact, freeze‑dried tablets, the method overcomes the limitations of liquid blood…

Guided terahertz pulse reflectometry with double photoconductive antenna

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Terahertz research image associated with Guided terahertz pulse reflectometry with double photoconductive antenna

The research team from Bordeaux and Limoges has engineered a compact, optics‑free terahertz imaging system that delivers high‑resolution reflectometry through a single hollow‑core waveguide. By integrating two photoconductive antennas on a single low‑temperature gallium arsenide chip and coupling…

Pilot study of freshly excised breast tissue response in the 300 – 600 GHz range

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Research figure associated with Terahertz refractive index-based morphological dilation for breast carcinoma delineation

The pilot research demonstrates that terahertz (THz) imaging in the 300‑600 GHz band can reliably distinguish between malignant and healthy breast tissues within freshly excised specimens. Because the refractive index of cancerous tissue mixtures is measurably higher than that of fat or normal…

Scanning laser terahertz near-field reflection imaging system

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Terahertz research image associated with Continuous-wave scanning terahertz near-field microscope

A new terahertz imaging platform has been introduced that reconciles the high sensitivity of terahertz (THz) radiation with the practical constraints of industrial and medical diagnostics. By focusing femtosecond pulses from a fiber‑coupled 1.56 µm laser onto a thin gallium arsenide crystal, the…

Low-frequency noise effect on terahertz tomography using thermal detectors

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Terahertz research image associated with Low-frequency noise effect on terahertz tomography using thermal detectors

Terahertz computed tomography (THz‑CT) offers a powerful, non‑contact imaging modality for security screening, material inspection and biomedical diagnostics, yet its practical deployment has been limited by the low photon energy of terahertz waves and the high noise levels inherent to thermal…

Room temperature Si–Ti thermopile THz sensor

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Research figure associated with Room temperature thermopile THz sensor

The work presents a room‑temperature terahertz (THz) detector based on a thermopile that converts absorbed THz radiation into a measurable voltage. The sensor’s absorber is a metallic grid engineered through a multilayer theoretical model that accounts for diffraction and equivalent resistivity,…

Review of Terahertz Tomography Techniques

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Terahertz research image associated with Review of terahertz tomography techniques

Terahertz (THz) imaging exploits the unique ability of 0.3–10 THz radiation to penetrate a wide range of dielectric materials while providing spectroscopic fingerprints of many chemical species. The reviewed work demonstrates that, beyond conventional two‑dimensional transmission or reflection…

Ex Vivo Breast Tumor Identification: Advances Toward a Silicon-Based Terahertz Near-Field Imaging Sensor

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Research figure associated with Terahertz refractive index-based morphological dilation for breast carcinoma delineation

An in-depth editorial guide to Ex Vivo Breast Tumor Identification: Advances Toward a Silicon-Based Terahertz Near-Field Imaging Sensor, its scientific context, terahertz contribution, applications, and collaboration potential in Biomedical Imaging.

NearSense – Advances Towards a Silicon-Based Terahertz Near-Field Imaging Sensor for Ex Vivo Breast Tumour Identification

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Research figure associated with Terahertz refractive index-based morphological dilation for breast carcinoma delineation

An in-depth editorial guide to NearSense – Advances Towards a Silicon-Based Terahertz Near-Field Imaging Sensor for Ex Vivo Breast Tumour Identification, its scientific context, terahertz contribution, applications, and collaboration potential in Biomedical Imaging.

An algorithm of unordered wavefront propagation in terahertz phase retrieval with dense multiplane data acquisition

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Research figure associated with An algorithm of unordered wavefront propagation in terahertz phase retrieval with dense multiplane data acquisition

An in-depth editorial guide to An algorithm of unordered wavefront propagation in terahertz phase retrieval with dense multiplane data acquisition, its scientific context, terahertz contribution, applications, and collaboration potential in Biomedical Imaging.

Feasibility of Using a 300 GHz Radar to Detect Fractures and Lithological Changes in Rocks

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Terahertz research image associated with Feasibility of Using a 300 GHz Radar to Detect Fractures and Lithological Changes in Rocks

The study demonstrates that a compact, frequency‑modulated continuous‑wave radar operating at 300 GHz can non‑destructively image rock interiors with unprecedented detail. By scanning a 121 cm² area in only fifteen minutes, the system resolves millimetre‑scale fractures and subtle lithological…

Terahertz refractive index-based morphological dilation for breast carcinoma delineation

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Research figure associated with Terahertz refractive index-based morphological dilation for breast carcinoma delineation

Terahertz time‑domain imaging has been harnessed to generate refractive‑index maps of freshly excised breast tissue, enabling a non‑ionising, optical‑based assessment of tumour margins during breast‑conserving surgery. By converting the refractive‑index distribution into a binary map and then…

Scanning point terahertz source microscopy of unstained comedo ductal carcinoma in situ

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Research figure associated with Scanning point terahertz source microscopy of unstained comedo ductal carcinoma in situ

Executive Summary Terahertz (THz) imaging has long promised a label‑free path to diagnosing cancers by exploiting the sensitivity of THz waves to tissue hydration, cellular density, and molecular composition. In breast cancer, the earliest precursor lesion—ductal carcinoma in situ (DCIS)—requires…

Terahertz near-field microscopy of ductal carcinoma in situ (DCIS) of the breast

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Research figure associated with Scanning point terahertz source microscopy of unstained comedo ductal carcinoma in situ

Executive Summary Recent research has demonstrated that terahertz (THz) near‑field microscopy can be employed to detect ductal carcinoma in situ (DCIS) – a pre‑invasive breast cancer that is notoriously difficult to identify during surgery due to its small size (50–500 µm). Conventional THz…

Label-Free Observation of Micrometric Inhomogeneity of Human Breast Cancer Cell Density Using Terahertz Near-Field Microscopy

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Terahertz research image associated with Label-Free Observation of Micrometric Inhomogeneity of Human Breast Cancer Cell Density Using Terahertz Near-Field Microscopy

Terahertz near‑field microscopy built around a scanning point terahertz source (SPoTS) achieves a spatial resolution of approximately ten micrometres, breaking the diffraction‑limited barrier that has traditionally constrained terahertz imaging to millimetre scales. By placing a formalin‑fixed,…

Single-scan multiplane phase retrieval with a radiation of terahertz quantum cascade laser

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Research figure associated with An algorithm of unordered wavefront propagation in terahertz phase retrieval with dense multiplane data acquisition

An in-depth editorial guide to Single-scan multiplane phase retrieval with a radiation of terahertz quantum cascade laser, its scientific context, terahertz contribution, applications, and collaboration potential in Biomedical Imaging.

NearSense – Advances Towards a Silicon-Based Terahertz Near-Field Imaging Sensor for Ex Vivo Breast Tumour Identification

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This paper present the terahertz near field resonator developed in the framework of Nearsense project and pulse time domain images used to determine the best frequency and design the resonator. Mavarani, L., Hillger, P., Bücher, T., Grzyb, J., Pfeiffer, U. R., Cassar, Q., … & MacGrogan, G. (2018). NearSense–Advances Towards a Silicon-Based Terahertz Near-Field Imaging … Read more

A Solid-State 0.56 THz Near-Field Array for μM-Scale Surface Imaging

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We This paper presents a fully-integrated 0.56 THz 128-pixel near-field 1-D sensor array with 10-12 μm lateral resolution. The sensing elements are based two parallel cross-bridged split-ring resonators that utilize a 3-D topology to exhibit high field confinement in the sensing spot. The sensor comprises a scalable excitation scheme that is designed to maximize the … Read more

Near-field wire-based passive probe antenna for the selective detection of the longitudinal electric field at terahertz frequencies

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Adam, R., Chusseau, L., Grosjean, T., Penarier, A., Guillet, J. P., & Charraut, D. (2009). Near-field wire-based passive probe antenna for the selective detection of the longitudinal electric field at terahertz frequencies. Journal of Applied Physics, 106(7), 073107.

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Coupling and propagation of Sommerfeld waves at 100 and 300 GHz

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The coupling between a linearly-polarized gaussian beam and a Sommerfeld wave propagating on a circular metallic wire is obtained owing to a differential phase element inserted in front of the metal wire. At millimeter-wavelengths we calculate a theoretical maximum coupling efficiency of 32% for this system in spite of the metal nature and radius in … Read more