1520nm激光激发的Er(05):FOG材料的上转换发光与立体显示研究

Up-Conversion Luminescence and Volumetric Display Research on Er(0.5): FOG Material Excited by 1 520 nm Laser

立体显示为现代重要的科学前沿。上转换三维立体显示为一种新颖的自体视三维立体显示,在1996年被评为十大科技创新成就之一,现正向应用快速发展。研究了1520nm半导体激光激发的Er(05)FOG材料的上转换发光,发现了(40743,41120nm),(52251m,52857nm),(54053m,54370,54900nm),(65475m,66550nm),和80210mnm的上转换发光(m代表主峰),依次为(2G4F2H)92→4I152,4H112→4I152,4S32→4I152,4F92→4I152和4I92→4I152的跃迁。值得注意的是上转换发光强度随激光功率变化的双对数曲线的斜率有各种各样的值。通过详细研究发现(40743,41120nm)的(2G4F2H)92→4I152上转换发光是四光子荧光;(52251m,52857nm)的2H112→4I152,(54053m,54370,54900nm)的4S32→4I152和(65475m,66550nm)的4F92→4I152的上转换发光为三光子荧光;而80210mnm的4I92→4I152上转换发光为双光子荧光。很明显从基态4I152到第一激发态的吸收很大,因为它的振子强度f和与1520nm激光的匹配都很好,随后的起源于第一激发态的能量传递和相继吸收都很易于发生,这导致了1520nm激光激发下的Er(05)FOG材料的丰富和有意义的上转换发光现象。

The volumetric display technology is one of the important science frontiers of modem society. Multi-photon up-conversion volumetric 3-D display, attractive especially in its self-spatial vision, has the advantages of total-solidification, high reliability and speedy operation so that it has a broad range of applications. The up-conversion luminescence of oxyfluoride glass material Er(0,5): FOG, when excited by 1 520 nm semiconductor laser, was studied. The common-fluorescence spectra were measured also, in order to know up-conversion sufficiently. It was found that there are several up-conversion luminescence lines (407.43, 411.20 nm), (522.51(m), 528.57 nm), (540.53(m), 543.70, 549.00 nm), (654.75(m), 665.50 nm) and 802.10(m) nm, which can be recognized as the fluorescence-transitions of ((2)G(4) F-2 H)(9/2) --> I-4(15/2), H-4(11/2) --> I-4(15/2), S-4(3/2) --> I-4(15/2), F-4(9/2) --> I-4(15/2) and I-4(9/2) --> I-4(15/2) respectively. It is interesting that the slopes of log F-log P curves, the double logarithmic variation of up-conversion luminescence intensity F with the laser power P, are various for these observed up-conversion luminescences, which are valuable for volumetric display. The comprehensive analysis found that the ((2)G(4) F-2 H)(9/2) --> I-4(15/2) up-conversion luminescence is a four photon up-conversion luminescence, while {H-2(11/2) --> I-4(15/2), S-4(3/2) --> I-4(15/2) and F-4(9/2) I-4(15/2)} up-conversion luminescence is three-photon up-conversion luminescences, and I-4(9/2) --> I-4(15/2) up-conversion luminescence is a two-photon up-conversion luminescence. It was found also that the absorption from the groundstate I-4(15/2) level to first excited level is very large, resulting in the fact that the sequential energy transfer and step-by-step absorption up-conversion are readily to happen.