High-Precise Spectrometry of the Terahertz Frequency Range: The Methods, Approaches and Applications

Вакс, В. Л.

doi:10.1007/s10762-011-9846-x

Cited by 41 publications

(24 citation statements)

References 18 publications

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“…The device operates at the most intensive absorption lines of exhaled biomarkers NO, NH3, acetone. In the radiation source of the spectrometer [17,21] the Gunn diode generator (97.5-117.5 GHz) together with the SL multiplier was used (Fig. 2).…”

Section: Specific Biomarker Detectormentioning

confidence: 99%

THz analyzers for breath research

Вакс

Домрачева

Chernyaeva

2016

2016 21st International Conference on Microwave, Radar and Wireless Communications (MIKON)

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Nowadays the methods of exhaled breath analysis are developing all around the world. The exhaled breath analysis can result in a powerful tool for noninvasive medicine. The gas analyzers for exhaled breath diagnostics are presented. The analyzers are based on high precise spectrometers of the THz frequency range, which provide high resolution and sensitivity for detecting the wide set of substances. The spectrometers work on effects of phase-switching and fast sweep of frequency. The analyzers have been successfully applied for detection of various biomarkers (nitric oxide, acetone, ammonia, methanol, ethanol) in breath of conditionally healthy volunteers and patients.Index Terms-High precise terahertz spectroscopy, phaseswitching, fast sweep of frequency, exhaled breath, biomarker

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Section: Specific Biomarker Detectormentioning

confidence: 99%

THz analyzers for breath research

Вакс

Домрачева

Chernyaeva

2016

2016 21st International Conference on Microwave, Radar and Wireless Communications (MIKON)

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“…Semiconductor superlattice (SSLs) can generate multiple harmonics from a GHz input and are more effective than Schottky diodes, which are the currently dominating technology for the GHz range. SSL multipliers have provided radiation up to 8.1 THz [15] and are the focus of this paper.…”

Section: Introductionmentioning

confidence: 99%

“…The principle underlying SSL multiplication [15] can be summarized as follows: perpendicular charge transport in biased superlattices is dominated by resonances due to the alignment of energy levels in different wells. These resonances yield various peaks in the current-voltage (I -V ) characteristics connected with negative differential conductivity [16,17].…”

Section: Introductionmentioning

confidence: 99%

Theory and measurements of harmonic generation in semiconductor superlattices with applications in the 100 GHz to 1 THz range

Pereira

Zubelli

Winge³

et al. 2017

Phys. Rev. B

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This manuscript describes harmonic generation in semiconductor superlattices, starting from a nonequilibrium Green's functions input to relaxation rate-type analytical approximations for the Boltzmann equation in which imperfections in the structure lead to asymmetric current flow and scattering processes under forward and reverse bias. The resulting current-voltage curves and the predicted consequences on harmonic generation, notably the development of even harmonics, are in good agreement with experiments. Significant output for frequencies close to 1 THz (7th harmonic) at room temperature, after excitation by a 141-GHz input signal, demonstrate the potential of superlattice devices for gigahertz to terahertz applications.

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“…Practical realization leads to strict requirements for THz radiation sources and receivers. The radiation source must be of high frequency stability (relative instability of 10 -8 -10 -9 ) and widely tunable [1]. The radiation source consists of a frequency synthesizer based on Gunn generator (112-115 GHz) and a semiconductor superlattice (SSL) frequency multiplier.…”

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confidence: 99%

High resolution THz gas spectrometer based on semiconductor and superconductor devices

et al. 2016

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Abstract. The high resolution THz gas spectrometer consists of a synthesizer based on Gunn generator with a semiconductor superlattice frequency multiplier as a radiation source, and an NbN hot electron bolometer in a direct detection mode as a THz radiation receiver was presented. The possibility of application of a quantum cascade laser as a local oscillator for a heterodyne receiver which is based on an NbN hot electron bolometer mixer is shown. The ways for further developing of the THz spectroscopy were outlined.The high resolution THz gas spectroscopy method is of great importance for different analytical applications, because the range contains the strongest rotation gas absorption lines. Practical realization leads to strict requirements for THz radiation sources and receivers. The radiation source must be of high frequency stability (relative instability of 10 -8 -10 -9 ) and widely tunable [1]. The radiation source consists of a frequency synthesizer based on Gunn generator (112-115 GHz) and a semiconductor superlattice (SSL) frequency multiplier. The SSL diode that is used in the frequency multiplier was grown with the molecular beam epitaxy method on GaAs/AlAs materials and is the sequence of 18 periods of alternating layers of GaAs and AlAs [2,3]. As a consequence of that the high number (up to 17) harmonics generated by the SSL have quite little power (less than nW), a low noise and high sensitive THz receiver is necessary. We applied the NbN superconductive hot electron bolometer (HEB) operating in the direct-detection mode [4,5].The test measurements of the water and deuterium water vapor spectral absorption lines with the spectrometer were performed at 1456-1495 GHz, 1680-1725 GHz and 1904-1955 GHz frequency bands. One of the absorption line spectra is presented at Fig. 1.A THz quantum cascade laser (QCL) [6] is prospective source of coherent radiation in the THz range. Phase locking (PLL) is needed for practical implementation of QCL in high resolution spectroscopy. We used 2 THz continuous wave (CW) mode QCL with output power around 1 mW. The carried out testing measurements showed the possibility of QCL phase locking and implementing for elaboration of a THz gas spectrometer. The QCL structure was soldered to copper plate holder, which was attached to a cold plate of a closed cycle cryostat. The QCL was operated at CW mode at the holder temperature about 15 K.The QCL radiation was collimated with external optics and then its radiation power was reflected by abeam splitter (3% reflectance) into a THz transparent optical window of a * Corresponding author: anfertev@ipmras.ru

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High-Precise Spectrometry of the Terahertz Frequency Range: The Methods, Approaches and Applications

Cited by 41 publications

References 18 publications

THz analyzers for breath research

THz analyzers for breath research

Theory and measurements of harmonic generation in semiconductor superlattices with applications in the 100 GHz to 1 THz range

High resolution THz gas spectrometer based on semiconductor and superconductor devices

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