Transfer of fluorescence light in laser-pumped dye-doped random media: influence of the dwell time of fluorescence in the medium and saturation of the exited state of dye molecules
Sergey S. Volchkov1, Ilya N. Mikhailov1,2, Angelika A. Klimova1, Ekaterina V. Ushakova1, Marina V. Alonova1, Dmitry A. Zimnyakov1,3
1Yury Gagarin State Technical University of Saratov, Saratov, Russia
2Institute of Radioengineering and Electronics, Saratov, Russia
3Precision Mechanics and Control Institute of RAS, Saratov, Russia
Abstract
The effect of narrowing of fluorescence spectra in dye-doped random media with increasing laser pump intensity was studied for Rhodamine6G-doped randomly structured polylactide matrices. This effect is usually interpreted as a transition from spontaneous fluorescence to random lasing. The experimental data obtained by pulse-periodic laser pumping of dye-doped matrices at the wavelength of 532 nm are considered in terms of the model of spectrally dependent incoherent amplification of the fluorescence. The key factor influencing the amplification (and, accordingly, the spectral narrowing) is the ratio between the average dwell time of fluorescence photons in the pumped medium and the characteristic amplification time. In turn, the average population of the excited state of dye molecules in the medium and the cross-section of stimulated emission determines the characteristic amplification time.
Speaker
Volchkov S.S.
Yuri Gagarin Saratov State Technical University
Russia
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