The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
Summary form only given. The physical nature of photoluminescence (PL) from semiconductor nanocrystals has been a subject of considerable debate. Earlier studies using organically-capped nanocrystals have shown that the PL arises primarily from dark excitonic states with a radiative lifetime of order microseconds. Recent advances in developing inorganically-capped nanocrystals have led to much improved...
Summary form only given. Incoherent emission (fluorescence and Raman scattering) of an ensemble of randomly oriented molecules is isotropic. However, when these molecules are homogeneously embedded in a sample shape (such as spheres, spheroids, cylinders, ...) which concentrates the internal intensity distribution, the resulting fluorescence emission can become anisotropic. Based on reciprocity principle,...
Summary form only given. The recent observation of an "atomic-like" AC Stark splitting in a semiconductor microcavity in which the Fabry-Perot mode is resonant with the fundamental quantum-well excitonic transition has opened the following question: is it possible to observe an AC Stark splitting when exciting in the exciton continuum? To answer this question we have studied the AC Stark...
Summary form only given. We exploit a high-quality semiconductor microcavity for the creation of an exciton gas near the optical saturation density. The sample is excited by short laser pulses that are resonant with both the cavity mode and the exciton transition. The microcavity provides a narrow spectral filter that strongly inhibits the photoexcitation of dissociated electron-hole pairs. On the...
Summary form only given. When a quantum-well exciton transition is resonant with a single mode of a high-Q microcavity, the normal modes ("cavity polaritons") of the coupled system are equal admixtures of the exciton and cavity. We have previously shown that, if the lower normal mode is excited by a phase-locked pair of optical pulses, the nonlinear response of a probe pulse tuned to the...
Summary form only given. The dynamics of polaritons in microcavity samples is presently under intense debate, in particular whether or not the so-called Boser action is possible. In this work, we investigate a /spl lambda/ cavity with a homogeneously broadened 25 nm GaAs quantum well at the antinode at a temperature of 10 K. We can thus inject well-defined polariton populations in k-space revealing...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.