Semiconductor nanowires (NWs) are fundamental structures for nanoscale devices. The excitation of NWs with laser beams results in thermal effects that can substantially change the spectral shape of the spectroscopic data. In particular, the interpretation of the Raman spectrum is greatly influenced by excitation induced temperature. A study of the interaction of the NWs with the excitation lase...

We investigate the dynamics of coherent optical phonons in tellurium after high-density excitation with femtosecond laser pulses. The data show a continuous redshift of the phonon frequency with increasing excitation density. Experiments with double-pulse excitation prove that the observed frequency shift is of purely electronic origin. We demonstrate that coherent phonons allow monitoring the ...

Photoacoustic methods can be used to make spatially resolved spectroscopic measurements of blood oxygenation when using a multiwavelength excitation source, such as an OPO system. Since these excitation sources are usually expensive and bulky, an alternative is to use laser diodes. A fibre coupled laser diode excitation system has been developed, providing two wavelengths, 850 and 905nm, each c...

The study of the interaction of ultrashort laser pulses with solids has raised some important questions concerning the nature of the transformations occurring at the material surface in the presence of very strong levels of electronic excitation. The existence of electronic excitation induced phase transitions has been already demonstrated in several materials (Si [1], GaAs [2–4], graphite [5])...

We describe a high-speed, two-frame shadowgraph method for the two-dimensional visualization of an expanding laser-induced plasma and shock wave in two time instances. The developed experimental method uses a 30 ps, green-laser, polarized pulse for the direct and delayed illumination separated by a variable time delay in the range from 300 ps to 30 ns. Since the exposed images of a single event...

Following a number of initial experiments using tunable diode laser selective excitation of lithium isotopes, published in the 1998-2003 period, there has been renewed and increased activity in the field. Here, a brief review of the selective laser excitation of Li isotopes is given. Emphasis is on the spectroscopy and requirements for laser isotope separation in Li. Also, the recent literature...

We have produced laser-cooled crystals of 232Th3+ in a linear rf Paul trap. This is the first time that a multiply charged ion has been laser cooled. Our work opens an avenue for excitation of the nuclear transition in a trapped, cold 229Th3+ ion. Laser excitation of nuclear states would establish a new bridge between atomic and nuclear physics, with the promise of new levels of metrological pr...

A single CW infrared laser beam can simultaneously trap and excite an individual colloidal quantum dot. Though the laser light is relatively weak, the excitation occurs through two-photon absorption. This finding eliminates the demand for an excitation light source in addition to a trapping laser in nanoscale experiments with simultaneous force-manipulation and quantum dot visualization. Also, ...