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Optimization of Hot-Electron Bolometers for THz Radiation

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Book Series: Karlsruher Schriftenreihe zur Supraleitung / Hrsg. Prof. Dr.-Ing. M. Noe, Prof. Dr. rer. nat. M. Siegel ISSN: 18691765 ISBN: 9783731500667 Year: Volume: 8 Pages: IX, 127 p. DOI: 10.5445/KSP/1000035742 Language: ENGLISH
Publisher: KIT Scientific Publishing
Subject: Technology (General)
Added to DOAB on : 2019-07-30 20:01:57
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Hot-electron bolometers are fast and low noise radiation detectors which can be used for many different applications. The aim of this work was to optimize the fabrication process of hot-electron bolometers and gain a deeper understanding of the underlying processes. To achieve this, the fabrication of the superconducting thin films was optimized and the superconducting properties of the films were analyzed. Detectors fabricated using the results showed a record value for the noise temperature.

Ultrabreitbandige Strahlungseinkopplung in THz-Detektoren

Author:
Book Series: Karlsruher Schriftenreihe zur Supraleitung / Hrsg. Prof. Dr.-Ing. M. Noe, Prof. Dr. rer. nat. M. Siegel ISSN: 18691765 ISBN: 9783731501022 Year: Volume: 11 Pages: IV, 246 p. DOI: 10.5445/KSP/1000036433 Language: GERMAN
Publisher: KIT Scientific Publishing
Subject: Technology (General)
Added to DOAB on : 2019-07-30 20:02:02
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Bolometric sensors show promising properties for the detection of THz radiation. To achieve an efficient coupling of the THz radiation into the detector, antenna structures with an ultra-high bandwidth have been developed in this work. By the use of the developed antennas the temporal resolution of ultra-short THz pulses on a picosecond time-scale has been enabled. Moreover, specific transient properties of THz signals, which have been measured for the first time, are demonstrated.

Charge Carrier Dynamics in Organometal Halide Perovskite Probed by Time-Resolved Electrical Measurements (Book chapter)

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ISBN: 9789535122456 Year: DOI: 10.5772/61631 Language: English
Publisher: IntechOpen Grant: FP7 Ideas: European Research Council - 226136
Subject: Science (General)
Added to DOAB on : 2019-01-17 11:48:00
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This chapter presents the fate of the charge carriers from the moment of its photogeneration in the perovskite to injection and transport into electrodes. Time-resolved electrical measurement techniques, terahertz (THz) spectroscopy and microwave (MW) conductivity, are primarily used to deconvolute ultrafast processes and to directly access behavior of charged species from the ps to µs timescales. Transient absorption and photoluminescence spectroscopy were also utilized to gain insight on carrier population dynamics and radiatively recombining charges. Photogenerated charged species were converted into highly mobile charges (µe = 12.5 cm2V-1s-1 and µh = 7.5 cm2V-1s-1) almost instantaneously (< 0.2 ps), while the remaining loosely bounded excitons dissociate into mobile charges after 2-3 ps. This high mobility is maintained for at least 1 ns as obtained by THz spectroscopy, while its lifetime is at least few tens of µs as measured by the MW conductivity technique. Lowering the temperature increases carrier mobilities with T-1.6.Dependence and a 75 meV barrier energy is required for temperature-activated recombination. Finally, injection of hole from MAPbI3 to Spiro-OMeTAD was found to be ultrafast and the state and population of dark holes dictate its recombination.

Diagnostics of Short Electron Bunches with THz Detectors in Particle Accelerators

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ISBN: 9783731508892 Year: Pages: XIII, 226 p. DOI: 10.5445/KSP/1000090017 Language: ENGLISH
Publisher: KIT Scientific Publishing
Subject: Technology (General)
Added to DOAB on : 2019-07-30 20:02:02
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Several novel diagnostic systems based on the detection of coherent THz radiation are presented. The investigation of the photon beam properties allow for bunch-by-bunch and turn-by-turn diagnostics of the emitting electron bunches in the accelerator. It is used for time-resolved studies of the micro-bunching instability. Accompanying simulations with Inovesa show a good agreement with the measurement which enhances the knowledge of the physics behind the micro-bunching instability.

Hollow core optical fibers

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ISBN: 9783039210886 / 9783039210893 Year: Pages: 182 DOI: 10.3390/books978-3-03921-089-3 Language: eng
Publisher: MDPI - Multidisciplinary Digital Publishing Institute
Subject: Technology (General) --- General and Civil Engineering
Added to DOAB on : 2019-08-28 11:21:27
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The possibility of guiding light in air has fascinated optical scientists and engineers since the dawn of optical fiber technology. In the last few years, hollow core optical fibers have been attracting the attention of an expanding worldwide research community, furthering the design, fabrication and device implementation of specialty optical fibers. Hollow core optical fibers are entering almost any specific application field of optics from medicine to security; from telecommunication to industrial processing; from instrumentation to biology. In parallel to the increased number of applications, major advances are still being made on the optimization of hollow core fiber designs and on the study of its underlying guiding properties, as well as in the use of different materials and fabrication techniques, which, in turn, are providing even more ways of exploitation of this technology and new technical challenges. This Special Issue of Fibers rides the wave of this increasing interest in the field of hollow core optical fibers by providing an overview of the recent progress in this field as well as an updated and indicative sample of current research activities worldwide.

High Precision X-Ray Measurements

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ISBN: 9783039213177 / 9783039213184 Year: Pages: 144 DOI: 10.3390/books978-3-03921-318-4 Language: eng
Publisher: MDPI - Multidisciplinary Digital Publishing Institute
Subject: Science (General) --- Physics (General)
Added to DOAB on : 2019-12-09 16:10:12
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Since their discovery in 1895, the detection of X-rays has had a strong impact on and various applications in several fields of science and human life. Impressive efforts have been made to develop new types of detectors and new techniques, aiming to obtain higher precision both in terms of energy and position. Depending on the applications, solid state detectors, microcalorimeters, and various types of spectrometers currently serve as the best options for spectroscopic and imaging detectors. Recent advancements in micron and meV precision have opened the door for groundbreaking applications in fundamental physics, medical science, astrophysics, cultural heritage, and several other fields. The aim of this Special Issue is to compile an overview, from different communities and research fields, of the most recent developments in X-ray detection and their possible impacts in various sectors, such as in exotic atom measurements, quantum physics studies, XRF, XES, EXAFS, plasma emission spectroscopy, monochromators, synchrotron radiation, telescopes, and space engineering. All the papers included in this Special Issue contribute to emphasizing the importance of X-ray detection in a very broad range of physics topics; most of these topics are covered by the published works, and several others are mentioned in the paper references, providing an interesting and very useful synopsis, from a variety of different communities and research fields, of the most recent developments in X-ray detection and their impact in fundamental research and societal applications.

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