Low-temperature time-resolved edge-luminescence excitation spectroscopy has been used to probe the exciton-polariton transport properties in CdS crystals of up to 3 mm thickness. We report the first direct experimental observation of edge luminescence excited by long-lived polaritons with lifetimes exceeding 400 ns which propagate from their origin at the front sample surface to the rear surfac...

We have developed a luminescence-measurement system for liquid bio/chemiluminescence that can obtain quantitative luminescence spectra as the absolute total number of luminescence photons at each wavelength or photon energy and quantum yields. Calibration of light-collection efficiency in the system is performed with a reference double-plate cell. This method is applicable to sample cells of an...

Nitrogen-doped graphene quantum dots (N-GQDs) were fabricated by microwave-assisted hydrothermal technique. The optical properties of the N-GQDs were studied. The luminescence of the N-GQDs can be tuned by varying the excitation wavelength. Furthermore, two-photon luminescence of the N-GQDs excited by near-infrared laser can be obtained. It is shown that N-doping play a key role on two-photon l...

Vibrio fischeri isolates from Euprymna scolopes are dim in culture but bright in the host. We found the luminescence of V. fischeri to be correlated with external osmolarity both in culture and in this symbiosis. Luminescence enhancement by osmolarity was independent of the lux promoter and unaffected by autoinducers or the level of lux expression, but the addition of an aldehyde substrate for ...

Manganese materials with attractive optical properties have been proposed for applications in such areas as photonics, light-emitting diodes, and bioimaging. In this paper, we have demonstrated multicolor Mn2+ luminescence in the visible region by controlling Ce3+-Mn2+ energy transfer in rare earth nanocrystals [NCs]. CeF3 and CePO4 NCs doped with Mn2+ have been prepared and can be well dispers...

Lanthanide-doped nanoparticles exhibit unique optical properties, such as a long luminescence lifetime (up to several milliseconds), sharp emission peaks, and upconversion luminescence over the range of wavelengths from near-infrared to visible. Exploiting these optical properties, lanthanide-doped nanoparticles have been widely utilized for cellular and small animal imaging with the absence of...

In this report, we present a facile approach for the synthesis of luminescent CdS and CdS:Mn+2 nanocrystals by reaction of CdSO4 and Na2S2O3 in the presence of thioglycerol (C3H8O2S) as capping agent. The influence of various experimental variables including, pH values and percentage of dopant, on the growth...

The visible luminescence caused by anodic oxidation of p-type porous silicon has been studied. It is shown that similar luminescence can be observed in n-type material by illumination with near-infrared light. Addition of a suitable reducing agent to the electrolyte solution can both suppress the oxidation of the porous layer and quench its luminescence. These results confirm a previously sugge...