Klaus Köhler

Jahre mit Paukenschlägen (9999)

Klaus Köhler

... Wie auch beim ersten Buch hat nur eine Auswahl des reichen Schaffens Aufnahme in die vorliegende Sammlung gefunden. Die Auswahl, diesmal von Autor selbst getroffen, fiel schwer, denn jedes...

Jahre mit Paukenschlägen (9999)

Klaus Köhler

... Wie auch beim ersten Buch hat nur eine Auswahl des reichen Schaffens Aufnahme in die vorliegende Sammlung gefunden. Die Auswahl, diesmal von Autor selbst getroffen, fiel schwer, denn jedes...

Influence of doping profiles on coherent acoustic phonon detection and generation in semiconductors (2008)

Hudert, Florian, Bartels, Albrecht, Dekorsy, Thomas, Köhler, Klaus

The doping profile in different n-doped GaAs homoepitaxial structures grown by molecular beam epitaxy is investigated in the time domain by employing a laser based picosecond ultrasound technique in...

The Photon Drag Effect: A Fast Fir Detector (2007)

Intersubband Absorption, Stephan Graf, Heinz Siegwart, Martin H. Kwakernaak, Bernd Margotte, Daniel Erni, ...

th-tunable free-electron laser source FELIX (Nieuwegein, The Netherlands). electrical optical W e developed an impedance and velocity matched photon drag detector [3]. The GaAs/AlGaAs multi-quantum...

Ultrafast photon drag detector for intersubband spectroscopy (2007)

Hans Sigg, Stephan Graf, Martin H. Kwakernaak, Bernd Margotte, Daniel Erni, Peter Van Son, ...

The photon drag effect of a 2D electron gas is measured using the ps infrared pulses of the wavelength-tunable free electron laser source FELIX. The pulsed photon drag response is found to depend...

High-speed asynchronous optical sampling for high-sensitivity detection of coherent phonons (2007)

Dekorsy, Thomas, Taubert, Richard, Hudert, Florian, Schrenk, Gerhard, Bartels, Albrecht, Cerna, Roland, ...

A new optical pump-probe technique is implemented for the investigation of coherent acoustic phonon dynamics in the GHz to THz frequency range which is based on two asynchronously linked femtosecond...

Femtosecond time-resolved optical pump-probe spectroscopy at kilohertz-scan-rates over nanosecond-time-delays without mechanical delay line (2006)

Bartels, Albrecht, Hudert, Florian, Janke, Christof, Dekorsy, Thomas, Köhler, Klaus

We demonstrate a technique for femtosecond time-resolved optical pump-probe spectroscopy that allows to scan over a nanosecond time delay at a kilohertz scan rate without mechanical delay line. Two...

Incorporation of Manganese and Iron into the Zirconia Lattice in Promoted Sulfated Zirconia Catalysts (2004)

Jentoft,Friederike C., Hahn,Alexander H. P., Kröhnert,Jutta, Lorenz,Gisela, Jentoft,Rolf E., Ressler,Thorsten, ...

Two series of Mn- or Fe-promoted zirconia samples were prepared, (i) a series of sulfated-free reference compounds via co-precipitation of aqueous solutions containing zirconium and the promoter...

Incorporation of Manganese and Iron into the Zirconia Lattice in Promoted Sulfated Zirconia Catalysts (2004)

Jentoft, Friederike C., Hahn, Alexander H. P., Kröhnert, Jutta, Lorenz, Gisela, Jentoft, Rolf E., Ressler, Thorsten, ...

Two series of Mn- or Fe-promoted zirconia samples were prepared, (i) a series of sulfated-free reference compounds via co-precipitation of aqueous solutions containing zirconium and the promoter...

Interaction between Promoters Mn/Fe, Sulfate, and Zirconia in Accordingly Composed Alkane Isomerization Catalysts (2004)

Jentoft, Friederike C., Hahn, Alexander, Wild, Ute, Klose, Barbara S., Jentoft, Rolf E., Ressler, Thorsten, ...

Interaction between Promoters Mn/Fe, Sulfate, and Zirconia in Accordingly Composed Alkane Isomerization Catalysts F.C. Jentoft, A. Hahn, U. Wild, B.S. Klose, R.E. Jentoft, T. Ressler, R. Schlögl...

Konzeption und Realisierung eines Bookmarkverwaltungssystemes für eine Stadtbücherei auf der Basis von PHP und MySQL (2003)

Köhler, Klaus

Die hier vorliegende Arbeit umfasst die Konzeption und Realisierung eines webbasierten Bookmarkverwaltungssystems fürdie Stadtbücherei in Stuttgart. In diesem speziell für dieStadtbücherei...

Power RF-Operation of AlGaN/GaN HEMTs Grown on Insulating Silicon Carbide Substrates (2002)

Lossy, Richard, Heymann, Peter, Würfl, Joachim, Chaturvedi, Nidhi, Müller, Stefan, Köhler, Klaus

We report on the technology and microwave characterization of AlGaN/GaN power HEMTs on SiC substrate. DC and S-parameter are discussed, together with load-pull results on devices up to 4mm gate...

Imaging of the Human Vomeronasal Duct (2001)

Abolmaali, Nasreddin D., Kühnau, Dorit, Knecht, Michael, Köhler, Klaus, Hüttenbrink, Karl-Bernd, Hummel, Thomas

The human vomeronasal duct (VND) is described as a tubular or pouch-like mucosal invagination of the anterior nasal septum. This study investigated shape, size and orientation of the VND using...

Observation of coherent zone-folded acoustic phonons generated by Raman scattering in a superlattice (2000)

Hawker, Philip, Kent, Anthony J., Challis, Lawrence J., Bartels, Albrecht, Dekorsy, Thomas, Kurz, Heinrich, ...

We have used pulse time-of-flight techniques to examine the phonon emission from an optically excited GaAs/AlAs superlattice structure. For laser excitation wavelengths shorter than 767 nm (the...

Midbandgap electro-optic detection of Bloch oscillations (2000)

Först, Michael, Segschneider, Gregor, Dekorsy, Thomas, Kurz, Heinrich, Köhler, Klaus

Bloch oscillations excited in a biased GaAs/AlxGa1-xAs superlattice are investigated in a time-resolved two-color electro-optic detection scheme. The detection of resonantly excited Bloch...

Coupled Bloch-Phonon Oscillations in Semiconductor Superlattices (2000)

Dekorsy, Thomas, Bartels, Albrecht, Kurz, Heinrich, Köhler, Klaus, Hey, Rudolf, Ploog, Klaus

We investigate coherent Bloch oscillations in GaAs/AlxGa1-xAs superlattices with electronic miniband widths larger than the optical phonon energy. In these superlattices the Bloch frequency can be...

Coherent zone-folded longitudinal acoustic phonons in semiconductor superlattices : excitation and detection (1999)

Bartels, Albrecht, Dekorsy, Thomas, Kurz, Heinrich, Köhler, Klaus

Coherent zone-folded acoustic phonons are excited in GaAs/AlAs superlattices by femtosecond laser pulses via resonant impulsive stimulated Raman scattering in both forward and backward scattering...

Coherent control of acoustic phonons in semiconductor superlattices (1998)

Bartels, Albrecht, Dekorsy, Thomas, Kurz, Heinrich, Köhler, Klaus

Coherent acoustic phonons are generated in GaAs/AlAs superlattices by excitation with femtosecond laser pulses. Several modes of the acoustic phonon spectrum are observed, in agreement with the...

Time-resolved study of intervalence band thermalization in a GaAs quantum well (1996)

Kim, A. M. T., Hunsche, Stefan, Dekorsy, Thomas, Kurz, Heinrich, Köhler, Klaus

The thermalization of optically excited cold holes in a GaAs quantum well is investigated by femtosecond two-color pump–probe measurements. Clear evidence is found for scattering from heavy-holes...

Bloch oscillations (1996)

Kurz, Heinrich, Roskos, Hartmut G., Dekorsy, Thomas, Köhler, Klaus

The status quo of the research on Bloch oscillations in semiconductor superlattices is outlined. Bloch oscillations excited by femtosecond laser pulses have been investigated by different optical...

Quantum coherence of continuum states in the valence band of GaAs quantum wells (1996)

Dekorsy, Thomas, Kim, A. M. T., Cho, Gyu Cheon, Hunsche, Stefan, Bakker, Huib J., Kurz, Heinrich, ...

Quantum beats of heavy and light holes in GaAs quantum wells are investigated in femtosecond time-resolved four-wave mixing and transmission experiments as a function of optical excitation energy....

Bloch oscillations at room temperature (1995)

Dekorsy, Thomas, Ott, R., Kurz, Heinrich, Köhler, Klaus

We report on the observation of coherent electronic wave-packet oscillations in a semiconductor heterostructure at room temperature. Bloch oscillations are excited in a wide-miniband...

Exceptionally slow dephasing of electronic continuum states in a semiconductor (1995)

Leisching, Patrick, Dekorsy, Thomas, Bakker, Huib J., Kurz, Heinrich, Köhler, Klaus

The coherent excitation of excitonic and continuum Wannier-Stark states in a semiconductor superlattice with femtosecond laser pulses leads to a modulation of both the interband and the intraband...

Electro-optic detection of Bloch oscillations (1994)

Dekorsy, Thomas, Leisching, Patrick, Köhler, Klaus, Kurz, Heinrich

The coherent motion of electronic wave packets in the Wannier-Stark regime of externally biased GaAs/AlxGa1-xAs superlattices is investigated by a time-resolved electro-optic technique. As predicted...

Internal field dynamics of coherent bloch oscillations in superlattices (1994)

Dekorsy, Thomas, Leisching, Patrick, Beck, Wolfgang, Ott, Reinhold, Dhaibi, Yousef, Schwedler, Ralf, ...

The dynamics of coherent wavepacket oscillations in GaAs/AlxGa1-xAs superlattices are investigated by transmittive electro-optic sampling (TEOS) with femtosecond time resolution. The internal...

Interaction between Promoters Mn/Fe, Sulfate, and Zirconia in Accordingly Composed Alkane Isomerization Catalysts

Jentoft,Friederike C., Hahn,Alexander, Wild,Ute, Klose,Barbara S., Jentoft,Rolf E., Ressler,Thorsten, ...

Interaction between Promoters Mn/Fe, Sulfate, and Zirconia in Accordingly Composed Alkane Isomerization Catalysts F.C. Jentoft, A. Hahn, U. Wild, B.S. Klose, R.E. Jentoft, T. Ressler, R. Schlögl...

Jahre mit Paukenschlägen

Klaus Köhler

... Wie auch beim ersten Buch hat nur eine Auswahl des reichen Schaffens Aufnahme in die vorliegende Sammlung gefunden. Die Auswahl, diesmal von Autor selbst getroffen, fiel schwer, denn jedes...