Time-domain imaging system in the terahertz range for immovable cultural heritage materials

In the field of cultural heritage science, the use of non‐destructive and contact‐free techniques has increased sharply over the past 10 years. Compared with conventional spectroscopic and imaging techniques such as X‐ray, ultraviolet, infrared, and laser spectroscopy, terahertz time‐domain imaging (THz‐TDI) is an innovative, non‐invasive, and safe technique, which provides good penetration depth (~1 cm) and broad spectral bandwidth (0.1–10 THz). This paper sets out the protocol and methodology for the application of THz‐TDI to immovable cultural heritage, illustrated by a series of case studies. The case studies demonstrate the efficacy of the technique in providing structural and material information for conservators

Terahertz (THz) biophotonics technology : instrumentation, techniques, and biomedical applications

Terahertz (THz) technology has experienced rapid development in the past two decades. Growing numbers of interdisciplinary applications are emerging, including material science, physics, communications, security, as well as biomedicine. THz biophotonics involves studies applying THz photonic technology in biomedicine, which has attracted attention due to the unique features of THz waves, such as the high sensitivity to water, resonance with biomolecules, favourable spatial resolution, capacity to probe the water-biomolecule interactions and non-ionizing photon energy. Despite the great potential, THz biophotonics is still at an early stage of development. There is a lack of standards for instrumentation, measurement protocols, and data analysis which makes it difficult to make comparisons among all the work published. In this article we give a comprehensive review of the key findings which have underpinned research into biomedical applications of THz technology. In particular, we will focus on the advances made in general THz instrumentation and specific THz-based instruments for biomedical applications. We will also discuss the theories describing the interaction between THz light and biomedical samples. We aim to provide an overview of both, basic biomedical research, as well as pre-clinical and clinical applications under investigation. The paper aims to provide a clear picture of the achievements, challenges and future perspectives of THz biophotonics

Chumnguh Thleum: Understanding Liver Illness and Hepatitis B Among Cambodian Immigrants

Cambodian immigrants are over 25 times more likely to have evidence of chronic hepatitis B infection than the general US population. Carriers of HBV are over 100 times more likely to develop liver cancer than non-carriers. Liver cancer incidence is the second leading cancer for Cambodian men and the sixth for Cambodian women. Despite this, this underserved population has received very little attention from health disparities researchers. Culturally and linguistically appropriate interventions are necessary to increase hepatitis B knowledge, serologic testing, and vaccination among Cambodian Americans. Eight group interviews were held with Cambodian American men (48) and women (49). Focus group discussion revealed unanticipated information about sociocultural influences on participants’ understanding about hepatitis B transmission, disease course, and prevention and treatment informed by humoral theories underlying Khmer medicine, by biomedicine, and by migration experiences. Our findings reveal the value of qualitative exploration to providing cultural context to biomedical information—a formula for effective health promotion and practice

Special Libraries, April 1933

Volume 24, Issue 3https://scholarworks.sjsu.edu/sla_sl_1933/1002/thumbnail.jp

The 2023 terahertz science and technology roadmap

Terahertz (THz) radiation encompasses a wide spectral range within the electromagnetic spectrum that extends from microwaves to the far infrared (100 GHz–∼30 THz). Within its frequency boundaries exist a broad variety of scientific disciplines that have presented, and continue to present, technical challenges to researchers. During the past 50 years, for instance, the demands of the scientific community have substantially evolved and with a need for advanced instrumentation to support radio astronomy, Earth observation, weather forecasting, security imaging, telecommunications, non-destructive device testing and much more. Furthermore, applications have required an emergence of technology from the laboratory environment to production-scale supply and in-the-field deployments ranging from harsh ground-based locations to deep space. In addressing these requirements, the research and development community has advanced related technology and bridged the transition between electronics and photonics that high frequency operation demands. The multidisciplinary nature of THz work was our stimulus for creating the 2017 THz Science and Technology Roadmap (Dhillon et al 2017 J. Phys. D: Appl. Phys. 50 043001). As one might envisage, though, there remains much to explore both scientifically and technically and the field has continued to develop and expand rapidly. It is timely, therefore, to revise our previous roadmap and in this 2023 version we both provide an update on key developments in established technical areas that have important scientific and public benefit, and highlight new and emerging areas that show particular promise. The developments that we describe thus span from fundamental scientific research, such as THz astronomy and the emergent area of THz quantum optics, to highly applied and commercially and societally impactful subjects that include 6G THz communications, medical imaging, and climate monitoring and prediction. Our Roadmap vision draws upon the expertise and perspective of multiple international specialists that together provide an overview of past developments and the likely challenges facing the field of THz science and technology in future decades. The document is written in a form that is accessible to policy makers who wish to gain an overview of the current state of the THz art, and for the non-specialist and curious who wish to understand available technology and challenges. A such, our experts deliver a 'snapshot' introduction to the current status of the field and provide suggestions for exciting future technical development directions. Ultimately, we intend the Roadmap to portray the advantages and benefits of the THz domain and to stimulate further exploration of the field in support of scientific research and commercial realisation

Coherent imaging using laser feedback interferometry with pulsed-mode terahertz quantum cascade lasers

We report a coherent terahertz (THz) imaging system that utilises a quantum cascade laser (QCL) operating in pulsed-mode as both the source and detector. The realisation of a short-pulsed THz QCL feedback interferometer permits both high peak powers and improved thermal efficiency, which enables the cryogen-free operation of the system. In this work, we demonstrated pulsed-mode swept-frequency laser feedback interferometry experimentally. Our interferometric detection scheme not only permits the simultaneous creation of both amplitude and phase images, but inherently suppresses unwanted background radiation. We demonstrate that the proposed system utilising microsecond pulses has the potential to achieve 0.25 mega-pixel per second acquisition rates, paving the pathway to video frame rate THz imaging