| 1. |
- Cherednichenko, Serguei, 1970, et al.
(author)
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16 Pixel HEB Heterodyne Receiver for 2.5 THz
- 2006
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In: in Proc.17th Intern. Symp. Space THz Technology, Paris, France, May. 2006..
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Conference paper (other academic/artistic)abstract
- A 16 pixel heterodyne receiver for 2.5 THz has been developed based on NbN superconducting hot-electron bolometer (HEB) mixers. The receiver uses a quasioptical RF coupling approach where HEB mixers are integrated into double dipole antennas on 1.5m thick Si3N4/ SiO2 membranes. Spherical mirrors (one per pixel) and backshort distance from the antenna have been used to design the output mixer beam profile. We present here the results of the antenna simulations using HFSS and ADS, as well as the beam calculations after the collimating mirror.
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| 2. |
- Cherednichenko, Serguei, 1970, et al.
(author)
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2.5THz multipixel heterodyne receiver based on NbN HEB mixers
- 2006
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In: Proc.SPIE. - 081946340X ; 6275, s. 62750I-1
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Journal article (peer-reviewed)abstract
- A 16 pixel heterodyne receiver for 2.5 THz has been developed based on NbN superconducting hot-electron bolometer (HEB) mixers. The receiver uses a quasioptical RF coupling approach where HEB mixers are integrated into double dipole antennas on 1.5m thick Si3N4/ SiO2 membranes. Spherical mirrors (one per pixel) and backshort distance from the antenna have been used to design the output mixer beam profile. The camera design allows all 16 pixel IF readout in parallel. The gain bandwidth of the HEB mixers on Si3N4/ SiO2 membranes was found to be 0.70.9 GHz, which is much smaller than for similar devices on silicon. Application of buffer layers and use of alternative types of membranes (e.g. silicon-on-insulator) is under investigation.
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| 3. |
- de Vera, Jean-Pierre, et al.
(author)
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Limits of Life and the Habitability of Mars : The ESA Space Experiment BIOMEX on the ISS
- 2019
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In: Astrobiology. - : Mary Ann Liebert. - 1531-1074 .- 1557-8070. ; 19:2, s. 145-157
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Journal article (other academic/artistic)abstract
- BIOMEX (BIOlogy and Mars EXperiment) is an ESA/Roscosmos space exposure experiment housed within the exposure facility EXPOSE-R2 outside the Zvezda module on the International Space Station (ISS). The design of the multiuser facility supports-among others-the BIOMEX investigations into the stability and level of degradation of space-exposed biosignatures such as pigments, secondary metabolites, and cell surfaces in contact with a terrestrial and Mars analog mineral environment. In parallel, analysis on the viability of the investigated organisms has provided relevant data for evaluation of the habitability of Mars, for the limits of life, and for the likelihood of an interplanetary transfer of life (theory of lithopanspermia). In this project, lichens, archaea, bacteria, cyanobacteria, snow/permafrost algae, meristematic black fungi, and bryophytes from alpine and polar habitats were embedded, grown, and cultured on a mixture of martian and lunar regolith analogs or other terrestrial minerals. The organisms and regolith analogs and terrestrial mineral mixtures were then exposed to space and to simulated Mars-like conditions by way of the EXPOSE-R2 facility. In this special issue, we present the first set of data obtained in reference to our investigation into the habitability of Mars and limits of life. This project was initiated and implemented by the BIOMEX group, an international and interdisciplinary consortium of 30 institutes in 12 countries on 3 continents. Preflight tests for sample selection, results from ground-based simulation experiments, and the space experiments themselves are presented and include a complete overview of the scientific processes required for this space experiment and postflight analysis. The presented BIOMEX concept could be scaled up to future exposure experiments on the Moon and will serve as a pretest in low Earth orbit.
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| 4. |
- Voigt, Robert, et al.
(author)
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Frequency stabilization of a terahertz quantum-cascade laser to the Lamb dip of a molecular absorption line
- 2023
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In: Optics Express. - 1094-4087 .- 1094-4087. ; 31:9, s. 13888-13894
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Journal article (peer-reviewed)abstract
- We demonstrate the frequency stabilization of a terahertz quantum-cascade laser (QCL) to the Lamb dip of the absorption line of a D2O rotational transition at 3.3809309 THz. To assess the quality of the frequency stabilization, a Schottky diode harmonic mixer is used to generate a downconverted QCL signal by mixing the laser emission with a multiplied microwave reference signal. This downconverted signal is directly measured by a spectrum analyzer showing a full width at half maximum of 350 kHz, which is eventually limited by high-frequency noise beyond the bandwidth of the stabilization loop.
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