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297 results on '"Strauß, U."'

11. Tracking the subsurface path of dislocations in GaN using scanning tunneling microscopy.

Author

Weidlich, P. H., Schnedler, M., Portz, V., Eisele, H., Strauß, U., Dunin-Borkowski, R. E., and Ebert, Ph.

Subjects
SCANNING tunneling microscopy, MICRO-optics, CARBON nanohorns, OPTOELECTRONIC devices, NANOSTRUCTURED materials, OPTICAL materials
Abstract

A methodology for the determination of the subsurface line direction of dislocations using scanning tunneling microscopy (STM) images is presented. The depth of the dislocation core is derived from an analysis of the displacement field measured by STM. The methodology is illustrated for dislocations at GaN(10̄10) cleavage surfaces. It is found that the dislocation line bends toward the surface, changing from predominantly edge-type to more screw-type character, when approaching the intersection point. Simultaneously, the total displacement detectable at the surface increases due to a preferred relaxation towards the surface. [ABSTRACT FROM AUTHOR]

Published
2015
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15. Band-to-band recombination in Ga0.5In0.5P

Author

Strauss, U., Ruhle, W.W., Queisser, H.J., Nakano, K., and Ishibashi, A.

Subjects
Gallium arsenide semiconductors -- Research, Semiconductors -- Plasma effects, Physics
Abstract

Time-resolved photoluminescence computations using transient spectra line-shape analysis examine the electron-hole plasma recombination properties in undoped, excited Ga(0.5)In(0.5)P, fabricated on GaAs substrates at 680 degrees Celsius. Auger effects are not detected and radiative recombination exists up to a high carrier concentration. Radiative recombination coefficients and an upper limit of the Auger coefficients are calculated. Uniform and random alloy samples contain similar recombination rates.

Published
1994

18. PROCEEDINGS OF VOLGA NEUROSCIENCE MEETING 2016 AND VOLGA NEUROSCIENCE SCHOOL 2016 Section MOLECULAR NEUROSCIENCE

Author

Storm, R., Schaub, T., Tarabykin, V.S., Bormuth, I., Yan, K., Grishina, O., Christou-Savina, S., Bezprozvanny, I., Schuster, S., Rivalan, M., Strauss, U., Rosario, M., Voss, A.K., Thomas, T., Nguyen, L., Hanashima, C., Studer, M., Belousova, I.I., Epifanova, E.A., Babaev, A.A., Mukhina, I.V., Rubenstein, J., Bourgognon, J., Steinert, J., Silver, D., Jabaudon, D., Kageyama, R., Goffinet, A., Matsuzaki, F., Cimadamore, F., Amador-Arjona, A., Huang, C., Terskikh, A., Gage, R., Mosienko, V., Teschemacher, A., Kasparov, S., Zessin, M., Boldt, C., Deisz, R., Loyola, S., Borschewski, A., McCormick, J., Tissir, F., Turovskaya, M.V., Turovsky, E.A., Boiko, A.S., Losenkov, I.S., Levchuk, L.A., Simutkin, G.G., Ivanova, S.A., Barrett, G.L., Naim, T., Trieu, J., and Huang, M.

Subjects
NEUROSCIENCE, VOLGA NEUROSCIENCE MEETING, MOLECULAR NEUROSCIENCE
Published
2016
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24. Lateral and longitudinal mode pattern of broad ridge 405 nm (Al, In)GaN laser diodes.

Author

Braun, H., Solowan, H.-M., Scholz, D., Meyer, T., Schwarz, U. T., Brüninghoff, S., Lell, A., and Strauß, U.

Abstract

The lateral mode profile of pulsed broad ridge 405 nm (Al, In)GaN laser diodes grown on GaN and SiC substrates, respectively, is investigated by temporal and spectral resolved scanning near-field optical microscopy. During the first microsecond of the pulse, we observe changes both in the spatial mode profile and in the spectral regime caused by thermal and carrier induced modification of the waveguide refractive index, before stable filaments build up. In quasi-cw operation, a correlation between the lateral mode profile and the corresponding spatial resolved longitudinal mode pattern can be found. The results show that different filaments have different effective refractive indices and thus build up separate longitudinal mode combs. [ABSTRACT FROM AUTHOR]

Published
2008
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25. Blue superluminescent light-emitting diodes with output power above 100mW for picoprojection

Author

Kopp, F., Eichler, C., Lell, A., Tautz, S., Ristic, J., Stojetz, B., Höß, C., Weig, T., Schwarz, U.T., Strauss, U., and Publica

Abstract

We present a blue InGaN research and development superluminescent light-emitting diode (SLED) that is suitable for picoprojection. The SLED reaches an output power of > 100mW with a peak wavelength of 443nm and a spectral bandwidth of > 2.6 nm as well as a single-mode far-field driven in cw mode at 25 °C. In order to figure out an optimized waveguide design, which enables such a high output power at lowest operation current, we compare the performance of diodes with curved and tilted shaped ridges in detail, using the lasing threshold current as a criterion for lasing or superluminescence, respectively.

Published
2013

27. Thermal resistance, gain, and antiguiding factor of GaN-based cyan laser diodes

Author

Scheibenzuber, W., Schwarz, U.T., Lermer, T., Lutgen, S., Strauss, U., and Publica

Subjects
antiguiding, III-nitrides, laser-diode, optical gain
Abstract

We present a highly precise method to determine the thermal resistance and the antiguiding factor of (Al,In)GaN laser diodes. Knowing the thermal resistance, we are able to exclude thermal effects and study the charge carrier density dependence of the optical gain and the refractive index. From these properties we determine the antiguiding factor. The method is applied to 489 nm (Al,In)GaN laser diodes with a high charge carrier density in the active region. For these laser diodes we find a high antiguiding factor of 10 +/- 1 at the laser wavelength.

Published
2011

29. Waveguide design of green InGaN laser diodes

Author

Lermer, T., Schillgalies, M., Breidenassel, A., Queren, D., Eichler, C., Avramescu, A., Müller, J., Scheibenzuber, W., Schwarz, U.T., Lutgen, S., Strauss, U., and Publica

Subjects
beam characteristic, InGaN, design, Laser, waveguide
Abstract

In this paper we investigate the waveguiding (WG) of direct green InGaN laser diodes grown on c-planeGaNsubstrates. The problem of parasitic modes emerges due to the reduced refractive index difference between the GaN waveguide and AlGaN cladding layers for green compared to blue emitting laser diodes. We discuss several approaches to avoid substrate modes. We investigate different materials and designs for optimized WG of green InGaN laser diodes using a 1D transfer matrix simulation tool.

Published
2010

34. High power T-Bars with narrow in-plane far-field angle

Author

Lauer, C., primary, Bachmann, A., additional, Gronninger, G., additional, Kreuter, P., additional, Furitsch, M., additional, Grossmann, V., additional, Leisner, M., additional, Sporrer, K., additional, Kissel, H., additional, Stoiber, M., additional, Biesenbach, J., additional, Konig, H., additional, and Strauss, U., additional

Published
2014
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37. Miscellaneous standard methods for Apis mellifera research

Author

Human, H., Brodschneider, R., Dietemann, V., Dively, G., Ellis, J.D., Forsgren, E., Fries, I., Hatjina, F., Hu, F.L., Jaffe, R., Jensen, A.B., Kohler, A., Magyar, J.P., Ouml;zkyrym, A., Pirk, C.W.W., Rose, R., Strauss, U., Tanner, G., Tarpy, D.R., van der Steen, J.J.M., Vaudo, A., Vejsnaes, F., de Wilde, J., Williams, G.R., Zheng, H.Q., Human, H., Brodschneider, R., Dietemann, V., Dively, G., Ellis, J.D., Forsgren, E., Fries, I., Hatjina, F., Hu, F.L., Jaffe, R., Jensen, A.B., Kohler, A., Magyar, J.P., Ouml;zkyrym, A., Pirk, C.W.W., Rose, R., Strauss, U., Tanner, G., Tarpy, D.R., van der Steen, J.J.M., Vaudo, A., Vejsnaes, F., de Wilde, J., Williams, G.R., and Zheng, H.Q.

Abstract

A variety of methods are used in honey bee research and differ depending on the level at which the research is conducted. On an individual level, the handling of individual honey bees, including the queen, larvae and pupae are required. There are different methods for the immobilising, killing and storing as well as determining individual weight of bees. The precise timing of developmental stages is also an important aspect of sampling individuals for experiments. In order to investigate and manipulate functional processes in honey bees, e. g. memory formation and retrieval and gene expression, microinjection is often used. A method that is used by both researchers and beekeepers is the marking of queens that serves not only to help to locate her during her life, but also enables the dating of queens. Creating multiple queen colonies allows the beekeeper to maintain spare queens, increase brood production or ask questions related to reproduction. On colony level, very useful techniques are the measurement of intra hive mortality using dead bee traps, weighing of full hives, collecting pollen and nectar, and digital monitoring of brood development via location recognition. At the population level, estimation of population density is essential to evaluate the health status and using beelines help to locate wild colonies. These methods, described in this paper, are especially valuable when investigating the effects of pesticide applications, environmental pollution and diseases on colony survival.

Published
2013

39. Carrier transport in green AlInGaN based structures on c-plane substrates

Author

Hager, T., primary, Binder, M., additional, Brüderl, G., additional, Eichler, C., additional, Avramescu, A., additional, Wurm, T., additional, Gomez-Iglesias, A., additional, Stojetz, B., additional, Tautz, S., additional, Galler, B., additional, Gerhard, S., additional, Zeisel, R., additional, and Strauss, U., additional

Published
2013
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43. IMPLEMENTATION OF WDM TECHNOLOGY FOR DATA TRANSMISSION OVER 50-m SI-POF BEYOND 20 Gb/s.

Author

Kruglov, R., Vinogradov, J., Loquai, S., Ziemann, O., Bunge, C.-A., Hager, T., and Strauss, U.

Subjects
OPTICAL fibers, OPTICAL links (Optical communications), DATA transmission systems, WAVELENGTH division multiplexing, SEMICONDUCTOR lasers
Abstract

We report the high-speed data transmission over 50-m link based on SI-POF with 1-mm core diameter employing WDM technology with six laser diodes operating at 405 nm, 442 nm, 459 nm, 490 nm, 515 nm and 655 nm. The data transmission was realized with 4-PAM and DMT modulation schemes. The record capacity of 21.4 Gb/s over 50-m SI-POF link was demonstrated with DMT modulation technique. Using 4-PAM a data rate of 20.5 Gb/s was achieved. [ABSTRACT FROM AUTHOR]

Published
2014

46. An industry perspective on the optimization of InGaN lasers and LEDs via modeling

Author

Gomez-Iglesias, A., primary, Sabathil, M., additional, Lermer, T., additional, Muller, J., additional, Galler, B., additional, Eichler, C., additional, Avramescu, A., additional, Dini, D., additional, Pietzonka, I., additional, Tautz, S., additional, Breidenassel, A., additional, Bruederl, G., additional, Lell, A., additional, Meyer, T., additional, Peter, M., additional, Lutgen, S., additional, Strauss, U., additional, Pasenow, B., additional, Koch, S. W., additional, Scheibenzuber, W., additional, and Schwarz, U. T., additional

Published
2011
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47. Sorafenib and dacarbazine as first-line therapy for advanced melanoma: phase I and open-label phase II studies

Author

Eisen, T, primary, Marais, R, additional, Affolter, A, additional, Lorigan, P, additional, Robert, C, additional, Corrie, P, additional, Ottensmeier, C, additional, Chevreau, C, additional, Chao, D, additional, Nathan, P D, additional, Jouary, T, additional, Harries, M, additional, Negrier, S, additional, Montegriffo, E, additional, Ahmad, T, additional, Gibbens, I, additional, James, M G, additional, Strauss, U P, additional, Prendergast, S, additional, and Gore, M E, additional

Published
2011
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