Upconversion luminescence from aluminoborate glasses doped with Tb^3+, Eu^3+ and Dy^3+ under the excitation of 26-μm femtosecond laser pulses

Abstract

We investigated the upconversion luminescence of three aluminoborate glasses doped with Tb(3+), Eu(3+), and Dy(3+) under the excitation of 2.6-μm femtosecond (fs) laser pulses. Efficient upconversion luminescence appearing in the visible light spectral region was observed in all three glasses and the emission spectra are quite similar to those obtained under single photon excitation. From the dependence of the luminescence intensity on the excitation intensity in the low excitation intensity regime, it was revealed that a four-photon process is involved in the generation of the upconversion luminescence in the Tb(3+)- and Eu(3+)-doped glasses while a mixed two- and three-photon process is involved in the Dy(3+)-doped glass. In the high excitation intensity regime, a reduction of the slope to about 1.0 was observed for all glasses. A physical mechanism based on the super saturation of the intermediate states of the rare-earth ions was employed to interpret the upconversion luminescence under the excitation of long-wavelength fs laser pulses. Significantly broadened luminescence spectra were observed in thick glasses under high excitation intensities and it can be attributed to the self-focusing of the laser beam in the thick glasses.

Self-assembled pearl-necklace patterned upconverting nanocrystals with highly efficient blue and ultraviolet emission: femtosecond laser based upconversion properties

“…It can be noted that upconversion luminescence properties with Fs-laser irradiation for different rare earth elements along with their applications were reported elsewhere. [50][51][52][53][54][55][56][57][58] Such as YVO4 single crystal upconversion luminescence was observed under infrared (IR) Fs-irradiation which resulted in broad characteristic emission in visible region (350-600 nm). 50 For, Ce 3+ doped YAP crystal, upconversion luminescence appeared in both ultraviolet and visible region under a focused 800 nm Fs-laser irradiation.…”

Printed Thin-Film Transistors: Research from China

“…As one of the core constituents in TFTs, the dielectric layer also plays a significance role on the device performance. Recently, some printable dielectric materials were developed for TFTs, such as inorganic oxide, polymers, ion-gel, solid-state electrolyte, and so on . Wu et al reported that poly­(methylsilsesquioxane) (PMSQ) could play as the gate insulator in IGZO TFTs by printable dielectric ink .…”

High-efficiency simultaneous three-photon absorption upconversion luminescence of a terbium-doped germanate glass

“…In recent years, owing to the rapid development of femtosecond (fs) lasers and their fabrication technology, which provided intense pulses at higher repetition rates and offered shorter pulse durations than conventional lasers, various MPA upconversion luminescence processes were demonstrated in Tb 3+ -doped ZnO-B 2 O 3 -SiO 2 glass, 6) silicate glass, 7,8) lutetium silicate powers, 9) and alumino-borate glasses. 5) These MPA processes were quite different from the conventional upconversion luminescence processes, the electrons were directly excited from the ground state to the excited state without the assistance of intermediate states.…”

“…4) Over the past decades, the upconversion luminescence of Tb 3+ was based on excited state absorption, energy transfer, cooperative upconversion, and photon avalanche. 5) It was largely due to the lack of high-intensity and shorterpulse lasers, which could not provide sufficiently high energy to induce a simultaneous MPA process. Thus, rarely has attention been centered on the upconversion luminescence of Tb 3+ based on simultaneous MPA luminescence.…”