Untersuchungen über die statistischen Schwankungen der infraroten Strahlung einer Hochdruck-Hochstrom-Argonentladung

1965 ◽  
Vol 20 (9) ◽  
pp. 1156-1169 ◽  
Author(s):  
W. Gubler ◽  
M. J. O. Strutt
Keyword(s):  
Infrared Detector ◽  
Photon Radiation ◽  
Continuous Emission ◽  
Spectral Radiation ◽  
Radial Temperature ◽  
Argon Discharge ◽  
Infrared Spectral ◽  
Dc Current ◽  
Spontaneous Fluctuations ◽  
Measured Distribution

An argon discharge at high pressure (up to 20 atmosph.) and large dc current is described. This discharge is used in the investigation of spontaneous fluctuations of photon radiation. Electron and ion densities are calculated as functions of pressure and temperature from which the continuous emission and absorption coefficients are determined. By comparing the calculated emission with the measured distribution of the infrared spectral radiation intensity in a disk of plasma, which is 0,2 mm in front of the cathode, the radial temperature distribution in the disk is determined. The temperature in the arc axis was found to be independent of the gas pressure and must be higher than 28 000°K. Investigations on electrical conductivity confirm the temperature distributions. Finally, the statistical radiation fluctuations can be calculated by means of the equations given in Part I and are compared with the experimental results. The infrared detector used for all these measurements is also described in Part I. A satisfactory coincidence between calculated and measured values was found.

scholarly journals A CMOS Compatible Pyroelectric Mid-Infrared Detector Based on Aluminium Nitride

Sensors ◽  
2019 ◽  
Vol 19 (11) ◽  
pp. 2513 ◽  
Author(s):  
Christian Ranacher ◽  
Cristina Consani ◽  
Andreas Tortschanoff ◽  
Lukas Rauter ◽  
Dominik Holzmann ◽  
...  
Keyword(s):  
Infrared Detector ◽  
Aluminium Nitride ◽  
Co2 Absorption ◽  
Absorption Region ◽  
Mid Infrared ◽  
Infrared Spectral Range ◽  
Wide Range ◽  
Infrared Spectral ◽  
Pyroelectric Material ◽  
Cmos Compatible

The detection of infrared radiation is of great interest for a wide range of applications, such as absorption sensing in the infrared spectral range. In this work, we present a CMOS compatible pyroelectric detector which was devised as a mid-infrared detector, comprising aluminium nitride (AlN) as the pyroelectric material and fabricated using semiconductor mass fabrication processes. To ensure thermal decoupling of the detector, the detectors are realized on a Si3N4/SiO2 membrane. The detectors have been tested at a wavelength close to the CO2 absorption region in the mid-infrared. Devices with various detector and membrane sizes were fabricated and the influence of these dimensions on the performance was investigated. The noise equivalent power of the first demonstrator devices connected to a readout circuit was measured to be as low as 5.3 × 10 − 9 W / Hz .

scholarly journals Continuous spectra of circumstellar envelopes of Be stars

1994 ◽  
Vol 162 ◽  
pp. 425-426
Author(s):  
D. Rohe-Koths ◽  
J. Dachs
Keyword(s):  
Line Emission ◽  
Circumstellar Disks ◽  
Balmer Line ◽  
Be Stars ◽  
Continuous Emission ◽  
Circumstellar Envelopes ◽  
Recombination Radiation ◽  
Infrared Spectral ◽  
Be Star ◽  
Central Stars

Line emission in Be star spectra is accompanied by continuous emission both in the Balmer continuum and in the infrared spectral region, due to the same process that is responsible for Balmer line emission, i.e. to recombination radiation from ionized hydrogen in the extended circumstellar disks surrounding the hot central stars.

Integrated Near-Infrared Spectral Sensor based on Near-Infrared Detector Arrays

2021 ◽  
Author(s):  
Kaylee D. Hakkel ◽  
Maurangelo Petruzzella ◽  
Fang Ou ◽  
Anne van Klinken ◽  
Francesco Pagliano ◽  
...  
Keyword(s):  
Near Infrared ◽  
Infrared Detector ◽  
Detector Arrays ◽  
Infrared Spectral

Untersuchungen über die statistischen Schwankungen der infraroten Strahlung einer Hochdruck-Hochstrom-Argonentladung

1965 ◽  
Vol 20 (8) ◽  
pp. 1011-1018 ◽  
Author(s):  
W. Gubler ◽  
M. J. O. Strutt
Keyword(s):  
Argon Plasma ◽  
Photon Radiation ◽  
Current Fluctuations ◽  
Homogeneous Plasma ◽  
Photon Noise ◽  
Thermal Photon ◽  
General Terms ◽  
Highly Sensitive ◽  
Bose Einstein ◽  
Spontaneous Fluctuations

By the Bose-Einstein statistics, the equations describing the spontaneous fluctuations of photon radiation are given. These equations are applied to the thermal photon radiation of a non homogeneous plasma. The fluctuations may be described by a degeneration factor μ which is calculated in general terms here and especially for an argon plasma in Part II. By using a highly sensitive photodetector which transforms radiation fluctuations into current fluctuations at its output, the degeneration factor μ can be determined. The properties of a cooled InSb-photodiode are then investigated. It is shown that this detector is useful for measuring photon noise at about 5 μ wavelength of an argon plasma. The actual measurements are given in Part II.

scholarly journals Level 0 to 1 processing of the imaging Fourier transform spectrometer GLORIA: generation of radiometrically and spectrally calibrated spectra

2014 ◽  
Vol 7 (12) ◽  
pp. 4167-4184 ◽  
Author(s):  
A. Kleinert ◽  
F. Friedl-Vallon ◽  
T. Guggenmoser ◽  
M. Höpfner ◽  
T. Neubert ◽  
...  
Keyword(s):  
Fourier Transform ◽  
Data Processing ◽  
Infrared Detector ◽  
Michelson Interferometer ◽  
Infrared Camera ◽  
Fourier Transform Spectrometer ◽  
Radiometric Calibration ◽  
Infrared Spectral ◽  
Research Aircraft ◽  
Intelligent Optimisation

Abstract. The Gimballed Limb Observer for Radiance Imaging of the Atmosphere (GLORIA) is an imaging Fourier transform spectrometer that is capable of operating on various high-altitude research aircraft. It measures the atmospheric emission in the thermal infrared spectral region in limb and nadir geometry. GLORIA consists of a classical Michelson interferometer combined with an infrared camera. The infrared detector has a usable area of 128 × 128 pixels, measuring up to 16 384 interferograms simultaneously. Imaging Fourier transform spectrometers impose a number of challenges with respect to instrument calibration and algorithm development. The optical setup with extremely high optical throughput requires the development of new methods and algorithms for spectral and radiometric calibration. Due to the vast amount of data there is a high demand for scientifically intelligent optimisation of the data processing. This paper outlines the characterisation and processing steps required for the generation of radiometrically and spectrally calibrated spectra. Methods for performance optimisation of the processing algorithm are presented. The performance of the data processing and the quality of the calibrated spectra are demonstrated for measurements collected during the first deployments of GLORIA on aircraft.

scholarly journals Level 0 to 1 processing of the imaging Fourier transform spectrometer GLORIA: generation of radiometrically and spectrally calibrated spectra

2014 ◽  
Vol 7 (3) ◽  
pp. 2827-2878 ◽  
Author(s):  
A. Kleinert ◽  
F. Friedl-Vallon ◽  
T. Guggenmoser ◽  
M. Höpfner ◽  
T. Neubert ◽  
...  
Keyword(s):  
Fourier Transform ◽  
Data Processing ◽  
Infrared Detector ◽  
Michelson Interferometer ◽  
Infrared Camera ◽  
Fourier Transform Spectrometer ◽  
Radiometric Calibration ◽  
Infrared Spectral ◽  
Research Aircraft ◽  
Intelligent Optimisation

Abstract. The Gimballed Limb Observer for Radiance Imaging of the Atmosphere (GLORIA) is an imaging Fourier transform spectrometer that is capable of operating on various high altitude research aircraft. It measures the atmospheric emission in the thermal infrared spectral region in limb and nadir geometry. GLORIA consists of a classical Michelson interferometer combined with an infrared camera. The infrared detector has a usable range of 128 × 128 pixels, measuring up to 16 384 interferograms simultaneously. Imaging Fourier transform spectrometers impose a number of challenges with respect to instrument calibration and algorithm development. The innovative optical setup with extremely high optical throughput requires the development of new methods and algorithms for spectral and radiometric calibration. Due to the vast amount of data there is a high demand for scientifically intelligent optimisation of the data processing. This paper outlines the characterisation and processing steps required for the generation of radiometrically and spectrally calibrated spectra. Methods for performance optimisation of the processing algorithm are presented. The performance of the data processing and the quality of the calibrated spectra are demonstrated for measurements collected during the first deployments of GLORIA on aircraft.

Thermal Radiation Absorption in Doped Semiconductors Due to Direct Intersubband Transitions

1995 ◽  
Vol 117 (4) ◽  
pp. 948-954 ◽  
Author(s):  
J. P. Hebb ◽  
E. G. Cravalho ◽  
M. I. Flik
Keyword(s):  
Thermal Radiation ◽  
Spectral Region ◽  
Optical Constants ◽  
Infrared Detector ◽  
Harmonic Oscillators ◽  
Radiation Absorption ◽  
Intersubband Transitions ◽  
Doped Semiconductors ◽  
Infrared Spectral ◽  
Quantum Mechanical Approach

This work proposes an engineering model for thermal radiation absorption due to direct intersubband transitions in doped semiconductors, which are excitations of bound electrons in the infrared spectral region. An existing quantum-mechanical approach is to model these transitions as a continuum of damped harmonic oscillators. This study modifies this approach to yield a more effective method for determining the optical constants of doped semiconductors. The room-temperature absorptance spectra of p-type GaAs samples with dopant concentrations from 8 × 1017 to 1 × 1020 cm-3 are measured using a Fourier transform–infrared spectrometer in the spectral region from 1.5 to 25 μm. The fitting of these spectra using the proposed model combined with the Drude and Lorentz models provides the optical constants and the dependence of the adjustable parameters on dopant concentration. The measured and fitted spectra agree closely. Potential applications of the model are semiconductor process control and infrared detector design.

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