Test of far-infrared atmospheric spectroscopy using wide-band balloon-borne measurements of the upwelling radiance

2008 ◽  
Vol 109 (6) ◽  
pp. 1030-1042 ◽  
Author(s):  
G. Bianchini ◽  
B. Carli ◽  
U. Cortesi ◽  
S. Del Bianco ◽  
M. Gai ◽  
...  
Keyword(s):  
Wide Band ◽  
Far Infrared ◽  
Atmospheric Spectroscopy

MBE Growth and Properties of Wide Band-Gap II-VI Strained-Layer Superlattice

1992 ◽  
Vol 242 ◽  
Author(s):  
Hailong Wang ◽  
Jie Cui ◽  
Aidong Shen ◽  
Liang Xu ◽  
Yunliang Chen ◽  
...  
Keyword(s):  
Structural Characteristics ◽  
Wide Band ◽  
Far Infrared ◽  
Atomic Layer ◽  
X Ray Diffraction ◽  
Wide Band Gap ◽  
Strained Layer ◽  
Pl Spectra ◽  
Reflectivity Spectra ◽  
Strained Layer Superlattice

ABSTRACTThe (ZnSe) /(ZnS ), strained layer super-lattices (SLSs) on (100) GaAs and (ZnTe)/(ZnSe) SLSs on (100) InP have been grown by molecular beam epitaxy (MBE) and atomic layer epitaxy (ALE). The structural characteristics of these SLSs were investigated in situ RHEED observation, low-angle X-ray diffraction spectra, TED image and AES analysis. The optical properties of the SLSs, such as refractive index of superlattice materials, photoluminescence (PL) spectra, transient PL spectra, Raman spectra, far-infrared reflectivity spectra and Optical nonlinear have been studied.

scholarly journals Prospects for Future Far-Infrared/Submillimeter Studies of the High-Redshift Universe

2002 ◽  
Vol 12 ◽  
pp. 493-496
Author(s):  
Andrew W. Blain
Keyword(s):  
Background Radiation ◽  
High Redshift ◽  
Wide Band ◽  
Far Infrared ◽  
High Mass ◽  
Background Intensity ◽  
Spectral Structure ◽  
Dusty Galaxies ◽  
Infrared Background ◽  
Balloon Experiments

AbstractObservations made usingCOBE, SCUBA,ISOand MAMBO have provided a reasonable working knowledge of both the intensity of the submm and far-infrared background radiation and the source counts of luminous high-redshift dusty galaxies. However, because there are uncertainties in the background intensity determinations, the samples of detected galaxies are small, and most importantly, their redshift distributions are very incomplete, details of the evolution of dusty galaxies remain unresolved. The next steps forward in the field will be the launches ofSIRTFandASTRO-F, the commissioning of SOFIA and new, more capable ground-based mm/submm-wave cameras - BOLOCAM, SHARC-II and SCUBA-II - the use of ultra-long duration balloon experiments, such as BLAST, the construction of ALMA and the arrival ofFIRST, and ultimately the advent of space-borne far-infrared interferometers, such asSPECS. There are also exciting prospects for direct mm/submm-wave CO-line redshift surveys using wide-band spectrographs. Using these new facilities, the number of high-redshift dusty galaxies known will be increased dramatically. Spectroscopy usingSIRTF, SOFIA andFIRSTwill probe the astrophysical processes within these sources in detail, hopefully addressing the open question of the fraction of the counts and background radiation that is generated by the formation of high-mass stars and by active galactic nuclei (AGNs). The spatial and spectral structure of distant dusty galaxies will finally be resolved in detail using ALMA andSPECS.

HAWC+, the Far-Infrared Camera and Polarimeter for SOFIA

2018 ◽  
Vol 07 (04) ◽  
pp. 1840008 ◽  
Author(s):  
Doyal A. Harper ◽  
Marcus C. Runyan ◽  
C. Darren Dowell ◽  
C. Jesse Wirth ◽  
Michael Amato ◽  
...  
Keyword(s):  
High Resolution ◽  
Magnetic Fields ◽  
Infrared Spectrum ◽  
Infrared Camera ◽  
Wide Band ◽  
Far Infrared ◽  
Infrared Astronomy ◽  
Dust Grains ◽  
Infrared Imager

High-resolution Airborne Wide-band Camera (HAWC[Formula: see text]) is the facility far-infrared imager and polarimeter for SOFIA, NASA’s Stratospheric Observatory for Infrared Astronomy. It is designed to cover the portion of the infrared spectrum that is completely inaccessible to ground-based observatories and which is essential for studies of astronomical sources with temperatures between tens and hundreds of degrees Kelvin. Its ability to make polarimetric measurements of aligned dust grains provides a unique new capability for studying interstellar magnetic fields. HAWC[Formula: see text] began commissioning flights in April 2016 and was accepted as a facility instrument in early 2018. In this paper, we describe the instrument, its operational procedures, and its performance on the observatory.

Seven-colour photometry at the Geneva Observatory

1966 ◽  
Vol 24 ◽  
pp. 262-266 ◽  
Author(s):  
M. Golay
Keyword(s):  
Wide Band ◽  
Electric System ◽  
Band Type

During the last 5 years, we have developed a seven-colour photometry at the Geneva Observatory. Our multicolour photo-electric system is of a wide-band type; the bandwidth being about 500Å for four filters. The three others are similar to theUBVsystem. In Table 1 we give the filter combinations used in our photometry (1).

TEM and cathodoluminescence of precipitates in II-VI semiconductors

1988 ◽  
Vol 46 ◽  
pp. 488-489
Author(s):  
Joanna L. Batstone
Keyword(s):  
Crystal Growth ◽  
Band Gap ◽  
Local Strain ◽  
Wide Band ◽  
Optoelectronic Device ◽  
Wide Band Gap ◽  
Bulk Crystal Growth ◽  
Transmission Electron ◽  
Device Applications ◽  
Stoichiometry Control

Interest in II-VI semiconductors centres around optoelectronic device applications. The wide band gap II-VI semiconductors such as ZnS, ZnSe and ZnTe have been used in lasers and electroluminescent displays yielding room temperature blue luminescence. The narrow gap II-VI semiconductors such as CdTe and HgxCd1-x Te are currently used for infrared detectors, where the band gap can be varied continuously by changing the alloy composition x.Two major sources of precipitation can be identified in II-VI materials; (i) dopant introduction leading to local variations in concentration and subsequent precipitation and (ii) Te precipitation in ZnTe, CdTe and HgCdTe due to native point defects which arise from problems associated with stoichiometry control during crystal growth. Precipitation is observed in both bulk crystal growth and epitaxial growth and is frequently associated with segregation and precipitation at dislocations and grain boundaries. Precipitation has been observed using transmission electron microscopy (TEM) which is sensitive to local strain fields around inclusions.

Electron microscopic characterization of diamond thin films and substrates for diamond heteroepitaxial growth

1989 ◽  
Vol 47 ◽  
pp. 592-593
Author(s):  
J.B. Posthill ◽  
R.P. Burns ◽  
R.A. Rudder ◽  
Y.H. Lee ◽  
R.J. Markunas ◽  
...  
Keyword(s):  
Thin Films ◽  
Wide Band ◽  
Deposition Process ◽  
Heteroepitaxial Growth ◽  
Electron Microscopic ◽  
Wide Band Gap ◽  
Lattice Matching ◽  
Different Types ◽  
Diamond Thin Films

Because of diamond’s wide band gap, high thermal conductivity, high breakdown voltage and high radiation resistance, there is a growing interest in developing diamond-based devices for several new and demanding electronic applications. In developing this technology, there are several new challenges to be overcome. Much of our effort has been directed at developing a diamond deposition process that will permit controlled, epitaxial growth. Also, because of cost and size considerations, it is mandatory that a non-native substrate be developed for heteroepitaxial nucleation and growth of diamond thin films. To this end, we are currently investigating the use of Ni single crystals on which different types of epitaxial metals are grown by molecular beam epitaxy (MBE) for lattice matching to diamond as well as surface chemistry modification. This contribution reports briefly on our microscopic observations that are integral to these endeavors.

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