共查询到6条相似文献,搜索用时 4 毫秒
1.
We consider the regime of strong light-matter coupling in an organic microcavity, where large Rabi splitting can be achieved. As has been shown, the excitation spectrum of such a structure, besides coherent polaritonic states, contains a number of strongly spatially localized incoherent excited states. These states form the majority of the excited states of the microcavity and are supposed to play the decisive role in the relaxation dynamics of the excitations in the microcavity. We consider the non-radiative transition from an incoherent excited state into one of the coherent states of the lower polaritonic branch accompanied by emission of a high-energy intramolecular phonon. It is shown that this process may determine the lifetime of incoherent excited states in the microcavity. This observation may be important in the discussion of pump–probe experiments with short pulses. This process may also play an important role for the population of the lowest energy states in organic microcavities, and hence in the problem of condensation of cavity polaritons. 相似文献
2.
R. Gehlhaar R. Schüppel M. Koschorreck T. Fritz H. Frb M. Hoffmann V.G.Lyssenko K. Leo L. Connolly J. Wenus D.G. Lidzey 《Journal of luminescence》2004,110(4):354-358
The optical properties of microcavities (MCs) are strongly dependent on both polarization of incident and emitted light and its angle of observation. Here we report the measurements of cw- and time-resolved photoluminescence (PL) observed at negative detuning and at resonance for s- and p-polarization in the strong coupling regime of a planar MC containing J-aggregates of a cyanine dye. Following non-resonant excitation, the emission spectra consist of three types of features: direct J-aggregate exciton emission, polariton emission, and uncoupled monomer emission through the transmission maxima of the distributed Bragg reflector beyond the stop-band. We compare our experimental results with a transfer-matrix calculation of the transmission for s- and p-polarization and explain the different positions of the polariton branches, the stop-band width, and the high- and low energy transmission maxima of the MC. Time-resolved PL experiments show an increase in the decay lifetime of the exciton-like mode when it is positioned far from the cavity mode. Close to resonance, the lower polariton branch decays with the natural lifetime of the J-aggregates. 相似文献
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Modified photoluminescence is demonstrated from the dye saturated porous silicon based single and coupled microcavities. When photonic cavity mode is weakly coupled to the emission states of the dye, photoluminescence line narrowing and intensity enhancement have been observed. Our experimental work and transfer matrix simulations and cavity modelling convincingly explain the tunability and optical field confinement within the microcavity. We also show that the photoluminescence enhancement is due to one-dimensional microcavity effect. These optically active hybrid materials from inexpensive fabrication may become an important consideration for many photonic applications. 相似文献
5.
In this work, CdSe nanocrystals (NCs) embedded in SiO2 matrix were grown by radio frequency (RF)-sputtering technique. X-ray technique was used to characterise the structural properties of the system. The NC's size was estimated to be around 4±1 nm in diameter. The temperature dependence of the photoluminescence from the CdSe/SiO2 system showed carriers thermal exchange between the NCs and deep defects in the matrix. The evolution of the excitonic energy emission with temperature is about 10 meV in the temperature range 15-295 K. This weak shift was explained by thermal mismatch between the matrix and the NCs. 相似文献
6.
Temperature dependence of luminescence emission from cerium- and europiumdoped MgO is reported. The emission intensity changes
with increase in the phosphor temperature. The phosphor showed peaks in the brightness-temperature curves. The intensities
at static temperatures were always lower, indicating that temperature quenching occurs in almost all cases. The same is also
evident from spectral distribution curves obtained at different temperatures. 相似文献