Fine Structure Of Emission Spectrum Research Articles

Ultrabroadband Tuning and Fine Structure of Emission Spectra in Lanthanide Er-Doped ZnSe Nanosheets for Display and Temperature Sensing.

Realizing multicolored luminescence in two-dimensional (2D) nanomaterials would afford potential for a range of next-generation nanoscale optoelectronic devices. Moreover, combining fine structured spectral line emission and detection may further enrich the studies and applications of functional nanomaterials. Herein, a lanthanide doping strategy has been utilized for the synthesis of 2D ZnSe:Er3+ nanosheets to achieve fine-structured, multicolor luminescence spectra. Simultaneous upconversion and downconversion emission is realized, which can cover an ultrabroadband optical range, from ultraviolet through visible to the near-infrared region. By investigating the low-temperature fine structure of emission spectra at 4 K, we have observed an abundance of sublevel electronic energy transitions, elucidating the electronic structure of Er3+ ions in the 2D ZnSe nanosheet. As the temperature is varied, these nanosheets exhibit tunable multicolored luminescence under 980 and 365 nm excitation. Utilizing the distinct sublevel transitions of Er3+ ions, the developed 2D ZnSe:Er3+ optical temperature sensor shows high absolute (15.23% K-1) and relative sensitivity (8.61% K-1), which is superior to conventional Er3+-activated upconversion luminescent nanothermometers. These findings imply that Er3+-doped ZnSe nanomaterials with direct and wide band gap have the potential for applications in future low-dimensional photonic and sensing devices at the 2D limit.

On the nature of the fine structure in emission spectra of XeCl laser

On the nature of the fine structure in emission spectra of XeCl laser

Fine structure of emission spectrum of a single-frequency injection laser

A theoretical analysis of single-frequency lasing is carried out in the framework of the quasimonochromatic field method with variable field amplitude and phase. The spectral optical-line profile, the spectral distribution of the laser output-power fluctuations, and the spectral distribution of the active-region density fluctuations (of the p-n voltage fluctuations) are obtained. In contrast to the known work in this field, the analysis in the present paper is carried out consistently starting with the wave equation and with account taken of the wavelike character of the radiation propagation in the active region. This has made it possible to express the final distributions in terms of quantities that are most readily measurable. Allowance for thermodynamic fluctuations has revealed an additional lasing-line broadening independent of the laser power. The analysis is not confined to lasing in the diode's own cavity, but takes into account also the possibility of using an external cavity, and corresponding varying the optical line spectral distributions, the output-power fluctuations, and p-n junction voltage fluctuations.

A generalized model of decay of multipole giant resonances

Within the quantum Green's function formalism, a generalized model of decay of multipole giant resonances is proposed. The model takes into account the complete basis of complex configurations (2p 2h, 3p 3h, etc.). The quasi-direct emission of particles from the doorway collective state is described in the shell model (taking account of fragmentation). The pre-equilibrium and equilibrium particle emission is considered within the microscopic model of pre-equilibrium decay, which makes it possible to account for the fine structure of emission spectra in experiments with good energy resolution. The features of the photoneutron emission spectrum have been analysed for the Z~ (7, n) reaction at E~ = 12 to 16 MeV.