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204 results on '"Giorgetta, F."'

1. Spectroscopy of the Methane {\nu}3 Band with an Accurate Mid-Infrared Coherent Dual- Comb Spectrometer

Author

Baumann, E., Giorgetta, F. R., Swann, W. C., Zolot, A. M., Coddington, I., and Newbury, N. R.

Subjects
Physics - Optics
Abstract

We demonstrate a high-accuracy dual-comb spectrometer centered at 3.4 \mu m. The amplitude and phase spectra of the P, Q, and partial R-branch of the methane {\nu}3 band are measured at 25 MHz to 100 MHz point spacing with ~kHz resolution and a signal-to-noise ratio of up to 3500. A fit of the absorbance and phase spectra yield the center frequency of 132 rovibrational lines. The systematic uncertainty is estimated to be 300 kHz, which is 10-3 of the Doppler width and a tenfold improvement over Fourier transform spectroscopy. These data are the first high- accuracy molecular spectra obtained with a direct comb spectrometer., Comment: journal article

Published
2011
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13. Dual-comb photoacoustic spectroscopy of a polymer film

Author

Friedlein, J. T., primary, Baumann, E., additional, Briggman, K. A., additional, Colacion, G. M., additional, Giorgetta, F. R., additional, Herman, D., additional, Hoenig, E. V., additional, Hwang, J., additional, Newbury, N. R., additional, Perez, E. F., additional, Yung, C. S., additional, Coddington, I., additional, and Cossel, K. C., additional

Published
2020
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16. Dual-comb spectroscopy with Si3N4 waveguides for gas spectroscopy in the 2 μm – 2.5 μm water window

Author

Baumann, E., primary, Hoenig, E. V., additional, Perez, E. F., additional, Colacion, G. M., additional, Giorgetta, F. R., additional, Cossel, K. C., additional, Ycas, G., additional, Carlson, D. R., additional, Hickstein, D. D., additional, Srinivasan, K., additional, Papp, S. B., additional, Newbury, N. R., additional, and Coddington, I., additional

Published
2019
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17. Mid-infrared quantum cascade detectors for applications inspectroscopy and pyrometry

Author

Hofstetter, D., Giorgetta, F., Baumann, E., Yang, Q., Manz, C., Köhler, K., Hofstetter, D., Giorgetta, F., Baumann, E., Yang, Q., Manz, C., and Köhler, K.

Abstract

In this paper, we give an overview of quantum cascade detector technology for the near- and mid-infrared wavelength range. Thanks to their photovoltaic operating principle, the most advanced quantum cascade detectors offer great opportunities in terms of high detection speed, reliable room temperature operation, and excellent Johnson noise limited detectivity. Besides some important features dealing with their fabrication and their general characteristics, we will also briefly present some possibilities for performance improvement. Elementary theoretical considerations adopted from photoconductive detectors confirm that optimization of such devices always involves various trade-offs

Published
2018

19. GaN/AlN short-period superlattices for intersubband optoelectronics: A systematic study of their epitaxial growth, design, and performance.

Author

Kandaswamy, P. K., Guillot, F., Bellet-Amalric, E., Monroy, E., Nevou, L., Tchernycheva, M., Michon, A., Julien, F. H., Baumann, E., Giorgetta, F. R., Hofstetter, D., Remmele, T., Albrecht, M., Birner, S., and Dang, Le Si

Subjects
SUPERLATTICES, OPTOELECTRONICS, EPITAXY, SUBSTRATES (Materials science), ABSORPTION spectra, ELECTRIC fields, QUANTUM wells, ABSORPTION
Abstract

We have studied the effect of growth and design parameters on the performance of Si-doped GaN/AlN multiquantum-well (MQW) structures for intersubband optoelectronics in the near infrared. The samples under study display infrared absorption in the 1.3–1.9 μm wavelength range, originating from the photoexcitation of electrons from the first to the second electronic level in the QWs. A commonly observed feature is the presence of multiple peaks in both intersubband absorption and interband emission spectra, which are attributed to monolayer thickness fluctuations in the quantum wells. These thickness fluctuations are induced by dislocations and eventually by cracks or metal accumulation during growth. The best optical performance is attained in samples synthesized with a moderate Ga excess during the growth of both the GaN QWs and the AlN barriers without growth interruptions. The optical properties are degraded at high growth temperatures (>720 °C) due to the thermal activation of the AlN etching of GaN. From the point of view of strain, GaN/AlN MQWs evolve rapidly to an equilibrium average lattice parameter, which is independent of the substrate. As a result, we do not observe any significant effect of the underlayers on the optical performance of the MQW structure. The average lattice parameter is different from the expected value from elastic energy minimization, which points out the presence of periodic misfit dislocations in the structure. The structural quality of the samples is independent of Si doping up to 1020 cm-3. By contrast, the intersubband absorption spectrum broadens and blueshifts with doping as a result of electron-electron interactions. This behavior is independent of the Si doping location in the structure, either in the QWs or in the barriers. It is found that the magnitude of the intersubband absorption is not directly determined by the Si concentration in the wells. Instead, depending on the Al mole fraction of the cap layer, the internal electric field due to piezoelectric and spontaneous polarization can deplete or induce charge accumulation in the QWs. In fact, this polarization-induced doping can result in a significant and even dominant contribution to the infrared absorption in GaN/AlN MQW structures. [ABSTRACT FROM AUTHOR]

Published
2008
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20. The role of sulfur dioxide in stratospheric aerosol formation evaluated by using in situ measurements in the tropical lower stratosphere

Author

Rollins, A. W., primary, Thornberry, T. D., additional, Watts, L. A., additional, Yu, P., additional, Rosenlof, K. H., additional, Mills, M., additional, Baumann, E., additional, Giorgetta, F. R., additional, Bui, T. V., additional, Höpfner, M., additional, Walker, K. A., additional, Boone, C., additional, Bernath, P. F., additional, Colarco, P. R., additional, Newman, P. A., additional, Fahey, D. W., additional, and Gao, R. S., additional

Published
2017
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22. Quantification of Variable Trace Gas Emissions across Large Regions using a Field-deployed Dual-comb Spectrometer

Author

Rieker, G.B., primary, Coburn, S.C., additional, Alden, C.B., additional, Wright, R.J., additional, Cossel, K.C., additional, Baumann, E., additional, Giorgetta, F., additional, Truong, G., additional, Newbury, N.R., additional, Faloona, I., additional, Conley, S., additional, Ghosh, S., additional, Prasad, K., additional, and Coddington, I., additional

Published
2017
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25. Horizontal stomach: a new sonographic clue to the antenatal diagnosis of right-sided congenital diaphragmatic hernia

Author

Conturso R, Giorgetta F, Bellussi F, YOUSSEF, ALY MOHAMED ALAAELDIN KAMALELDIN ALY, Tenore A, PILU, GIANLUIGI, RIZZO, NICOLA, GHI, TULLIO, Conturso R, Giorgetta F, Bellussi F, Youssef A, Tenore A, Pilu G, Rizzo N, and Ghi T

Subjects
PRENATAL DIAGNOSIS
Abstract

We report on two cases of isolated right-sided congenital diaphragmatic hernia (CDH) in which the condition was first suspected due to ultrasound visualization of a horizontal orientation of the fetal stomach in the abdomen. In the first case, a 38-year-old woman, gravida 2 para 1, attended the ultrasound department of Valduce Hospital, Como at 13 weeks’ gestation for a first-trimester scan. Fetal nuchal translucency thickness and anatomy appeared normal; however, an abnormal horizontal orientation of the fetal stomach was noted (Figure 1). At 20 weeks’ gestation, a massive protrusion of the liver into the fetal chest was documented, leading to the diagnosis of isolated right-sided CDH. Moderate lung hypoplasia was demonstrated (observed to expected lungto- head ratio was 41%, according to the longest diameter method)1. Antenatal findings were confirmed after birth and neonatal death occurred soon after delivery.

Published
2013

26. Intrapartum transperineal ultrasound assessment of fetal head progression in active second stage of labor and mode of delivery

Author

Ghi T., Youssef A., Maroni E., Arcangeli T., De Musso F., Bellussi F., Nanni M., Giorgetta F., Morselli Labate A.M., Iammarino M.T., Paccapelo A., Cariello L., RIZZO, NICOLA, PILU, GIANLUIGI, Ghi T., Youssef A., Maroni E., Arcangeli T., De Musso F., Bellussi F., Nanni M., Giorgetta F., Morselli-Labate AM., Iammarino MT., Paccapelo A., Cariello L., Rizzo N., and Pilu G.

Subjects
Adult, Imaging, Three-Dimensional, Time Factors, SECOND STAGE OF LABOR, Labor Stage, Second, Pregnancy, Humans, Female, LABOR, Delivery, Obstetric, Sensitivity and Specificity, ULTRASOUND, Ultrasonography, Prenatal
Abstract

OBJECTIVE: To compare longitudinal changes in angle of progression (AoP) and midline angle (MLA) during the active second stage of labor according to the mode of delivery. METHODS: A three-dimensional transperineal ultrasound volume was acquired in a series of nulliparous women at the beginning of the active second stage (T1) and every 20 min thereafter (T2, T3, T4, T5 and T6). Following delivery, all ultrasound volumes were analyzed and AoP and MLA were measured. RESULTS: Among 71 women included in the study, 58 underwent spontaneous vaginal delivery (group A) and 13 underwent operative delivery (group B) (eight by vacuum extraction and five by Cesarean section). When compared with Group B, Group A had a wider AoP only at T1 (140.0 +/- 20.2 degrees vs. 122.9 +/- 16.7 degrees ; P = 0.010) and T2 (149.7 +/- 20.7 degrees vs. 126.9 +/- 17.5 degrees ; P = 0.006). MLA was narrower in group A only at T3 (21.2 +/- 11.7 degrees vs. 40.8 +/- 27.9 degrees ; P = 0.043), T4 (18.2 +/- 15.0 degrees vs. 47.4 +/- 29.6 degrees ; P = 0.020) and T5 (18.3 +/- 6.0 degrees vs. 34.7 +/- 4.2 degrees ; P = 0.034). On stepwise forward multiple logistic regression analysis, both AoP and MLA were independently associated with operative delivery (OR = 0.955 and OR = 1.018, respectively). CONCLUSION: Ultrasonographic assessment of fetal head descent in the second stage of labor may play a role in the prediction of the mode of delivery.

Published
2012

28. Dual-Comb spectroscopy for GHG quantification

Author

Coddington, I., primary, Truong, G.W., additional, Waxman, E., additional, Cossel, K., additional, Schroeder, P.J., additional, Wright, R.J., additional, Coburn, S., additional, Giorgetta, F. R., additional, Swann, W. C., additional, Rieker, G. B., additional, and Newbury, N. R., additional

Published
2016
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29. Optical Synchronization of Clocks across a 12-km Turbulent Air Path over a City

Author

Sinclair, L. C., primary, Bergeron, H., additional, Swann, W. C., additional, Nelson, C. W., additional, Coddington, I., additional, Baumann, E., additional, Giorgetta, F. R., additional, Khader, I., additional, Cermak, M., additional, Newbury, N. R., additional, Petrillo, K. G., additional, Juarez, J. C., additional, Souza, K. T., additional, Dennis, M. L., additional, and Deschênes, J.-D., additional

Published
2016
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30. Frequency Comb Measurements Through Turbulent Paths

Author

Coddington, I., primary, Truong, G.W., additional, Waxman, E., additional, Cossel, K., additional, Schroeder, P.J., additional, Wright, R.J., additional, Coburn, S., additional, Sodergren, B., additional, Giorgetta, F. R., additional, Swann, W. C., additional, Rieker, G. B., additional, and Newbury, N. R., additional

Published
2016
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31. Spectroscopy of the Methane ��3 Band with an Accurate Mid-Infrared Coherent Dual- Comb Spectrometer

Author

Baumann, E., Giorgetta, F. R., Swann, W. C., Zolot, A. M., Coddington, I., and Newbury, N. R.

Subjects
Physics::Instrumentation and Detectors, FOS: Physical sciences, Optics (physics.optics)
Abstract

We demonstrate a high-accuracy dual-comb spectrometer centered at 3.4 ��m. The amplitude and phase spectra of the P, Q, and partial R-branch of the methane ��3 band are measured at 25 MHz to 100 MHz point spacing with ~kHz resolution and a signal-to-noise ratio of up to 3500. A fit of the absorbance and phase spectra yield the center frequency of 132 rovibrational lines. The systematic uncertainty is estimated to be 300 kHz, which is 10-3 of the Doppler width and a tenfold improvement over Fourier transform spectroscopy. These data are the first high- accuracy molecular spectra obtained with a direct comb spectrometer., journal article

Published
2011
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