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Showing 1 to 17 of 17 for “"Far Infrared (FIR)"”.
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Optical Characterization of Thin Metallic and Semiconducting Films in the Far Infrared
The performance in a cw optically pumped far infrared (fir) laser of a hybrid metal mesh-dielectric mirror consisting of an assembly of thin metallic and semiconducting films is evaluated. Its construction is described and an overview of theoretical approaches predicting its optical properties is …
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Exploring the challenges of a far-infrared post-dispersed polarising Fourier transform spectrometer
Recent advances in superconducting far-infrared (FIR) bolometer detectors have resulted in increases to their sensitivity of at least two orders of magnitude over broadband detectors flown on previous far-infrared spaceborne astronomy instruments. Such sensitivity means that observations employing …
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DESIGN, CONSTRUCTION, AND SCIENCE FORECASTS FOR THE TERAHERTZ INTENSITY MAPPER
… Intensity Mapper (TIM). TIM isa balloon-borne far infrared (FIR) telescope fielding novel cryogenic kinetic inductance detectors. TIM combines two long-slit grating spectrometers to cover 240-420 microns at a resolving power of R = 250. Building on the flight heritage of the BLAST and SPIDER …
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Identification and Characterization of Shallow Impurity States in Gallium-Arsenide and Indium-Phosphide Using Photothermal Ionization Spectroscopy
A model of far infrared (FIR) dielectric response of shallow impurity states in a semiconductor has been developed and is presented for the specific case of the shallow donor transitions in high purity epitaxial GaAs. The model is quite general, however, and should be applicable with slight …
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Identification and characterization of shallow impurity states in gallium arsenide and indium phosphide using photothermal ionization spectroscopy
A model of far infrared (FIR) dielectric response of shallow impurity states in a semiconductor has been developed and is presented for the specific case of the shallow donor transitions in high purity epitaxial GaAs. The model is quite general, however, and should be applicable with slight …
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Mid-Infrared Studies of Galactic sources: Probing the Relationship Between Polycyclic Aromatic Hydrocarbons and their Physical Environment
Over the past 50 years, prominent mid-infrared (MIR) emission features from 3--20 $mu$m have been observed ubiquitously in the interstellar medium (ISM) of Galactic and extragalactic sources. These emission features arise from the vibrational relaxation of polycyclic aromatic hydrocarbons (PAHs) …
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Polarimetry measurements of current density profile and fluctuation changes during lower hybrid experiments on Alcator C-Mod
… measurements. A three-chord poloidally viewing far-infrared (FIR) polarimeter has therefore been developed for C-Mod. FIR optics, FIR detectors, electronics and mechanical components were custom designed and fabricated. Various sources of vibrations and systematic errors have been carefully …
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Infrared to millimetre observations of active galaxies
… measurements of the continuum emission at infrared (IR) to millimetre wavelengths from the nuclear regions of a number of active galaxies. In particular many observations have been made for the first time in the submillimetre regime. The observing methods at these wavelengths and the unique …
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The automated detection and multiwavelength properties of LADUMA HI galaxies
… created in this work will be used to clean the first public data release of the LADUMA data cubes, which will be outlined in an upcoming paper. We present the confirmed SoFiA-2 detections of HI and compare the results to those produced by manual and semi-automated methods of source finding. We …
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Far-infrared superradiance in methyl fluoride
… laser operated on the P(20) line at 9.55 ~m. The far-infrared (FIR) super-radiant pulses, at a wavelength of 496 microns, were identified by the pressure (p) dependence of their widths and delays (inversely proportional to p) and their intensities (as p2). These pulses were observed by a fast, …
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Towards multiple quantum well optically pumped far infrared lasers
… are a potential coherent source in the far infrared (FIR) wavelengths. The FIR (~ 30 to 300 µm) is a region within the electromagnetic spectrum that has seen relatively little development. No practical solid-state lasers have been possible in the FIR, which is also referred to as the …
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Quantum dot-based semiconductor Terahertz transceiver systems
… (ps), or optical signals with wavelengths in the far-infrared (FIR) range. High absorption of THz signals in atmosphere via absorption by molecules such as H2O also impeded early developments and is a key issue in THz systems even today.<br/> There is now a wide variety of THz system solutions, …
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Evolution of the Circumstellar Atomic and Molecular Envelopes Around Evolved Stars
… for objects at different epochs of evolution. Far-infrared (FIR) spectra were taken for 24 evolved stars, including the line emission of [O I], [C II], [Si I], [Si II], [S I], [Fe I], [Fe II], and [Ne II]. Atomic emission was found only in those sources where Teff ≥ 10000 K. With higher T …
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Stimulated Raman and hyper-Raman scattering in the FIR region
Submitted by Carolyn Mead (cmead2@illinois.edu) on 2011-06-28T13:59:43Z No. of bitstreams: 1 1980_kim.pdf: 2258540 bytes, checksum: 8fe0d75ab8a852db2e65274e4407c4b5 (MD5)
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Experimental correlation and self consistent analysis of an IR, FIR, MW triple resonant system in ammonia
Submitted by Carolyn Mead (cmead2@illinois.edu) on 2011-06-16T15:27:49Z No. of bitstreams: 1 1981_lee.pdf: 3513032 bytes, checksum: 36bd5d66a8713ce2d64e8fa53101d808 (MD5)
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Effects of Far Infrared Irradiation on Vascular Function in Healthy Subjects
<b>Introduction</b>: far infrared (FIR) is an invisible electromagnetic wave and a source of heat. It is involved in a range of biological effects which includes improvement in clinical outcomes in many pathological diseases especially in patients with chronic heart failure. FIR was also employed …
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Designing subwavelength-structured light sources
… lasers of varying frequencies, powers, and far-field properties. In science, the laser is a useful source in spectroscopy and microscopy, for investigating nonlinear optics phenomena and nuclear fusion. More commonly, we find them in barcode readers, laser pointers, and printers. They are …