Upconversion luminescence of Er3+-doped YSZ single crystals

Luminescence properties of ytterbium and erbium doped silica–zirconia nanostructured optical fiber under near infrared excitation

“…The electrons of the populated 4 F 7/2 level decay nonradiatively by multiphonon relaxation until the 2 H 11/2 and 4 S 3/2 levels, which decay radiatively to the ground state 4 I 15/2 . According to the previous studies [14,17,18] on the influence of the nanocrystaline environment of erbium ions in zirconia xerogels on their visible emission, we note the sharp shape of the green emission band observed in the output of the pumped fiber. The well defined splits correspond to the different Stark degeneracy of the erbium 4 S 3/2 and 2 H 11/2 levels caused by the applied crystal field of the local environment.…”

NIR to Visible Up‐conversion Luminescence of Er3+‐Doped PMN‐PT Transparent Ceramics

“…The predominant mechanisms of up‐conversion in Er 3+ ‐doped materials are excited state absorption (ESA) and ET . Usually in diluted Er 3+ ‐doped system, up‐conversion mechanism is ascribed to ESA, which is independent of erbium content; whereas up‐conversion emission due to ET processes is enhanced with increasing Er 3+ concentration because of short distance between neighboring Er 3+ ions …”

“…The predominant mechanisms of up-conversion in Er 3+doped materials are excited state absorption (ESA) and ET. 37,38 Usually in diluted Er 3+ -doped system, up-conversion mechanism is ascribed to ESA, which is independent of erbium content 39,40 ; whereas up-conversion emission due to ET processes is enhanced with increasing Er 3+ concentration because of short distance between neighboring Er 3+ ions. 41 The diode laser with emission wavelength of 980 nm gives rise to electronic transition from the ground state, 4 I 15/2 , to the excited 4 I 11/2 level by the ground state absorption (GSA) process.…”

Up-conversion luminescence saturation under pulsed excitation of erbium-doped, SiO2–TiO2 sol–gel powders

“…Up-conversion luminescence opens the possibility for the fabrication of visible or even ultraviolet lasers, low intensity IR imaging, hot emission and avalanche like co-doped systems and biological applications [9]. The most common excitation processes that produce up-conversion luminescence are energy transfer and excited state absorption (ESA) [10][11][12]. The luminescence intensity from ESA processes is independent of erbium content, whereas up-conversion emissions due to energy transfer processes are increased for higher erbium content, and when the distance among Er 3 + is reduced as a consequence of cluster formation [13][14][15].…”