A coherent transceiver using a THz quantum cascade (TQCL) laser as the transmitter and an optically pumped molecular laser as the local oscillator has been used, with a pair of Schottky diode mixers in the receiver and reference channels, to acquire high-resolution images of fully illuminated targets, including scale models and concealed objects. Phase stability of the received signal, sufficient to allow coherent image processing of the rotating target (in azimuth and elevation), was obtained by frequency-locking the TQCL to the free-running, highly stable optically pumped molecular laser. While the range to the target was limited by the available TQCL power (several hundred microwatts) and reasonably strong indoor atmospheric attenuation at 2.408 THz, the coherence length of the TQCL transmitter will allow coherent imaging over distances up to several hundred meters. Image data obtained with the system is presented.
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http://dx.doi.org/10.1364/OE.18.016264 | DOI Listing |
Data Brief
February 2025
SCES, Strathmore University, Nairobi, Kenya.
Quantum Cascade Lasers (QCL) are promising semiconductor lasers, compact and powerful, but of complex design. Availability of structured data of the QCL properties can support data mining activities that seek to understand the relationship between these properties, for instance between the design and performance features. The main open source of QCL data is in scientific text which in most cases is usually unstructured.
View Article and Find Full Text PDFWe propose an alternative scheme for implementing the antibunching effects of two-magnon bundle in a hybrid ferromagnet-superconductor system, where a magnon mode from the yttrium iron garnet (YIG) sphere interacts with a three-level superconducting qubit via photon virtual excitation in the microwave cavity. With the help of the qubit driving from the ground state to the excited state, the cascaded emission of magnon occurs and then the two-magnon bundle is formed. By analyzing the ordinary and generalized second-order correlation functions, it is found that the antibunched two-magnon bundle could be achieved via properly choosing the system parameters, which is originated from the anharmonicity of dressed energy levels induced by magnon-qubit couplings.
View Article and Find Full Text PDFAdv Sci (Weinh)
January 2025
Department of Biomaterials & Biomedical Technology (BBT), University Medical Centre Groningen (UMCG), Antonius Deusinglaan 1, Groningen, 9713 AV, The Netherlands.
Free radicals are believed to play a secondary role in the cell death cascade associated with various diseases. In Huntington's disease (HD), the aggregation of polyglutamine (PolyQ) not only contributes to the disease but also elevates free radical levels. However, measuring free radicals is difficult due to their short lifespan and limited diffusion range.
View Article and Find Full Text PDFChemSusChem
January 2025
Kwansei Gakuin University: Kansei Gakuin Daigaku, Department of Applied Chemistry for Environment, 1 Gakuen-Uegahara, 669-1330, Sanda, JAPAN.
The natural Z-scheme of oxygenic photosynthesis efficiently drives electron transfer from photosystem II (PSII) to photosystem I (PSI) via an electron transport chain, despite the lower energy levels of PSII. Inspired by this sophisticated mechanism, we present a layered cascade bio-solar cell (CBSC) that emulates the Z-scheme. In this design, chlorophyll derivatives (Chl) act as PSI analogs, while bacteriochlorophyll derivatives (BChl) serve as PSII analogs in the active layer.
View Article and Find Full Text PDFChirality
January 2025
JASCO Corporation, Japan.
A vibrational circular dichroism (VCD) instrument having a thermoelectrically cooled detector (denoted as a TEC unit) was constructed in this study. An electronic device, instead of liquid nitrogen, was employed in the instrument to cool the detector. The feasibility of the system was examined by recording the VCD spectra of liquid pinenes and insect wings.
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