Concept

Two-photon absorption

Related publications (165)

Nanoscale depth-resolved coherent femtosecond motion in laser-excited bismuth

We employ grazing-incidence femtosecond x-ray diffraction to characterize the coherent, femtosecond laser-induced lattice motion of a bismuth crystal as a function of depth from the surface with a temporal resolution of 193 +/- 8 fs. The data show direct c ...

American Physical Society2008

On the excitation wavelength dependence of the fluorescence of bacteriorhodopsin

Majed Chergui, Erwin Portuondo Campa, Goran Zgrablic, Stefan Haacke, Selma Schenkl

We present a systematic study of the time-integrated fluorescence of native bacteriorhodopsin, as a function of excitation wavelength across the visible absorption band. While the fluorescence max. is unaffected, the spectrum broadens on the high-energy si ...

2007

The Light at the End of the Tunnel Junction - Improving the Energy Resolution of UV Single-Photon Spectrometers using Diffusion Engineering

Andreea Veronica Savu

We present experimental results which test whether diffusion engineering can increase the energy resolution of a single-photon superconducting tunnel-junction spectrometer. When a UV photon is absorbed in superconducting Al, it creates an excess number of ...

Yale University2007

Ultrafast Nonadiabatic Dynamics of [FeII(bpy)3]2+ in Solution

Majed Chergui, Frank van Mourik, Andrea Cannizzo, Wojciech Gawelda, Van Thai Pham

The ultrafast relaxation of aq. Fe(II)-tris(bipyridine) upon excitation into the singlet metal-to-ligand charge-transfer band (1MLCT) was characterized by femtosecond fluorescence up-conversion and transient absorption (TA) studies. The fluorescence expt. ...

2007

Grating interferometer based scanning setup for hard x-ray phase contrast imaging

Christian David

In x-ray radiography, particularly for technical and industrial applications, a scanning setup is very often favorable when compared to a direct two-dimensional image acquisition. Here, we report on an efficient scanning method for grating based x-ray phas ...

2007

Single Photon Imaging in CMOS

Edoardo Charbon

CMOS single photon detectors enable large pixel arrays and integrated ancillary circuits. As a consequence, higher timing accuracy and reduced power consumption can be achieved at lower costs. This paper discusses applications and implementation considerat ...

2006

Optimization of the efficiency of single photon sources based on quantum dots under optical excitation

Elyahou Kapon, Daniel Oberli, Martin Henrik Baier

We demonstrate efficient, regulated single-photon operation from site-controlled InGaAs quantum dots (QDs) grown on a prepatterned substrate. Under nonresonant optical excitation, carriers trapped at structural or compositional defects of the adjacent nano ...

American Institute of Physics2006

Simultaneous Multicolor Fluorescence Cross-Correlation Spectroscopy to Detect Higher Order Molecular Interactions Using Single Wavelength Laser Excitation

Theo Lasser

Fluorescence cross-correlation spectroscopy is a powerful method for the study of molecular interactions and dynamics in solution and even in living cells. Usually, in the optical setup, either two laser beams have to be superimposed in their respective co ...

2006

Optical injection of charge current in quantum wires: oscillations induced by excitonic effects

Benoît Marie Joseph Deveaud, Marc-André Dupertuis, Daniel Marti

We investigate the charge current that is optically injected by interference between one- and two-photon excitation in the presence of excitonic effects. We consider a realistic V-shaped quantum wire excited slightly below the band gap by two simultaneous ...

2005

Femtosecond time-resolved absorption processes in lithium niobate crystals

Demetri Psaltis

Femtosecond pump pulses are strongly attenuated in lithium niobate owing to two-photon absorption; the relevant nonlinear coefficient beta(p) ranges from similar to 3.5 cm/GW for lambda(p) = 388 nm to similar to 0.1 cm/GW for 514 nm. In collinear pump-prob ...

2005

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