西安建筑科技大学教师个人主页 Dangli Gao--Home-- Up/down conversion switching by adjusting the pulse width of red laser beams in LaF3: Tm3+ nanocrystals

Up/down conversion switching by adjusting the pulse width of red laser beams in LaF3: Tm3+ nanocrystals

Release time:2024-08-09

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Key Words:: 中文关键字：上/下转换开关；激光脉宽；LaF3:Tm3+纳米晶体，英文关键字：Up/down conversion switching；pulse width；LaF3:Tm3+

Abstract:: We demonstrate a versatile approach to fine-tuning the ratio of blue to near-infrared emission intensity from Tm3+ ions in LaF3 nanocrystals by adjusting the pulse widths and excitation wavelengths of red laser beams. The mechanism of color-tunable Tm3 emission by pulse widths is explored, and a mechanism based on promoting the population of some luminescence levels and cutting off the population of others by suitably adjusting pulse duration is proposed. The underlying reason of excitation wavelength-modulated emission is ascribed to tuning absorption probability ratio of ground state absorption to excited state absorption by tuning the matching degree between the energies of excitation wavelength and ground (excited) state absorption of Tm3. The ability of our LaF3:Tm3+ nanocrystals to emit variable emissions on demand in response to pulse width and excitation wavelength provides keen insights into controlling the population processes of luminescent levels and offers a versatile approach for tuning the spectral output.