| 1. |
- Beleckaite, I., et al.
(author)
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Characterization of non-vertically aligned semiconductor nanowires by THz emission measurements
- 2016
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In: 41st International Conference on Infrared, Millimeter and Terahertz Waves, IRMMW-THz 2016. - 9781467384858 ; 2016-November
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Conference paper (peer-reviewed)abstract
- In this work terahertz (THz) pulse emission of the non-vertically aligned GaAs core-shell nanowires (NWs) is investigated. THz emission azimuthal dependencies of different NW samples have been measured. It is shown that these measurements together with theoretical calculations could be a very promising method to determine the effective index of refraction (n0) of the NW ensemble. The measurement of azimuthal dependencies are confirmed to be a much more sensitive way for measuring n0 than traditional THz TDS method.
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| 2. |
- Garcia Wernersson, Joakim, et al.
(author)
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Non-destructive density measurements of pharmaceutical products by THz imaging
- 2016
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In: International Conference on Infrared, Millimeter, and Terahertz Waves, IRMMW-THz. - 2162-2027 .- 2162-2035. - 9781467384858 ; 2016-November, s. Art. no 7758615-
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Conference paper (peer-reviewed)abstract
- In this paper, measurements with a THz imaging system at 346 GHz together with electromagnetic simulations have demonstrated the capability of THz sensing for the non-destructive density determination of intermediate products in the pharmaceutical industry. The results confirm the ability of THz imaging to detect density changes in pharmaceutical samples by measuring the phase variation of the wave transmitted through the sample.
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| 3. |
- Katona, Gergely, 1975, et al.
(author)
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Bayesian analysis of non-thermal structural changes induced by terahertz radiation in protein crystals
- 2016
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In: 2016 41ST INTERNATIONAL CONFERENCE ON INFRARED, MILLIMETER, AND TERAHERTZ WAVES (IRMMW-THZ). - New York : IEEE conference proceedings. - 2162-2027 .- 2162-2035. - 9781467384858
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Conference paper (peer-reviewed)abstract
- We have periodically (25ms on - 25ms off) illuminated lysozyme crystals with 0.4 THz radiation and simultaneously monitored their X-ray diffraction intensity in order to study non-thermal structural changes in the protein. In this work we analyze the X-ray scaled and unmerged diffraction intensity observations using a multivariate Bayesian model in order to improve the accuracy of the intensity estimates. The diffraction intensity pairs of the illuminated and non-illuminated state show a predominantly positive correlation. The correlation decreases with increasing resolution suggesting that finer slicing and faster sampling of the rocking curve may further improve the accuracy and effect size of structure factor amplitude differences, making the interpretation of structural changes more straightforward. The improved analysis retains the most important structural features described previously (in helix 3) and provide addition details about the B-factor changes close to the substrate binding site.
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| 4. |
- Marouf Rashid, Hawal, 1982, et al.
(author)
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Experimental Verification of the pumping of SIS mixer with an Distributed SIS Frequency Doubler
- 2016
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In: International Conference on Infrared, Millimeter, and Terahertz Waves, IRMMW-THz. - 2162-2027 .- 2162-2035. - 9781467384858 ; 2016-November, s. Art. no. 7758974-
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Conference paper (peer-reviewed)abstract
- In this paper, we present the performance of the first frequency multiplier using the non-linearity of distributed SIS junctions. The prototype doubler based on distributed SIS junction was for the first time able to pump an SIS mixer. The multiplication efficiency of the distributed SIS junction is 15-30 % for a fractional bandwidth of 10% with excellent spectral line purity. The measured -3 dB line width of the multiplied signal is better than 1 Hz, which was limited by the resolution bandwidth of the spectrum analyzer. The results attained in this work show that the distributed SIS junction frequency multipliers have considerable future potential, and could possibly be used in LO source in single-end and multi-pixel SIS mixer receivers.
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| 5. |
- Novoselov, Evgenii, 1988, et al.
(author)
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Wideband THz HEB mixers using HPCVD MgB2 thin films
- 2016
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In: International Conference on Infrared, Millimeter, and Terahertz Waves, IRMMW-THz. - 2162-2027 .- 2162-2035. - 9781467384858 ; 2016-November, s. Arti no 7758933-
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Conference paper (peer-reviewed)abstract
- We present results of experimental study of the gain bandwidth (GBW) of MgB2 hot electron-bolometer (HEB) mixers at 0.1THz and 0.4THz. Antenna integrated 0.25-1.5um2 area devices were made from thin MgB2 films deposited with a custom made HPCVD system. Film as thin as 15-45nm had a Tc from 35K to 40K. The GBW was found to be independent on the bias conditions, the bath temperature, and the LO frequency. The maximum GBW of 6GHz was observed for 15nm thick HEBs. At an 0.7THz LO and a 23K bath temperature the receiver noise temperature of this mixer was 3000K (corrected for optical losses).
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| 6. |
- Sundström, Villy
(author)
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Electron dynamics in solar energy converting materials
- 2016
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In: 41st International Conference on Infrared, Millimeter and Terahertz Waves, IRMMW-THz 2016. - 9781467384858
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Conference paper (peer-reviewed)abstract
- Solar energy is the most abundant renewable energy source available. Conversion of light into electricity and chemical energy are the two major paths for solar energy conversion. Nanostructured organic and hybrid materials are being explored for applications in photovoltaic solar energy conversion, as well as photocatalysis for solar fuel generation. Light harvesting, energy transport, charge photogeneration and recombination, charge transport are the elementary processes accounting for the conversion of light energy into useful charge carriers. We show how a combination of time resolved spectroscopy, with a focus on TR-THz spectroscopy, covering the time scales from femtoseconds to milliseconds is a powerful tool to study the light induced processes and provide mechanistic information valuable for design of novel or optimized materials.
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| 7. |
- Tu, Chien Ming, et al.
(author)
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Helicity-dependent terahertz radiation from topological insulator Sb2Te3 thin film by femtosecond optical excitation
- 2016
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In: 41st International Conference on Infrared, Millimeter and Terahertz Waves, IRMMW-THz 2016. - 9781467384858
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Conference paper (peer-reviewed)abstract
- We report on terahertz radiation from topological insulator (TI) Sb2Te3 thin film under ultrafast optical excitation with different helicity. Polarity-reversals of the emitted THz radiation were observed as the helicity of optical pulses reversed. The observed phenomena are coincident with the characteristics of the helicity-dependent photocurrent on TIs. Our work demonstrates the potential applications of surface photocurrents on TIs for opto-spintronics devices.
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| 8. |
- Töpfer, Fritzi, et al.
(author)
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Diagnosis of malignant melanoma by micromachined near-field millimeter-wave probe
- 2016
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In: International Conference on Infrared, Millimeter, and Terahertz Waves, IRMMW-THz. - : IEEE. - 9781467384858
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Conference paper (peer-reviewed)abstract
- A micromachined millimeter-wave probe, optimized for early-stage skin tumor diagnosis has been verified using a murine skin cancer model. Malignant melanoma tumors are clearly distinguishable from surrounding healthy tissue, since the difference in S11 between a malignant melanoma skin tumor and surrounding healthy tissue is 6.7 times larger than typical standard deviations of measurements on the same spot. Furthermore, the probe has an 8 times higher selectivity to a tumor growing in the skin close to the surface as compared to a subcutaneous tumor buried beneath a thick healthy tissue layer. This confirms the optimized sensitivity of the probe to the targeted upper portion of the skin, in which skin tumor growth starts in malignant melanoma patients.
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