NIR to visible upconversion in Er3+-doped fluoride glass under 1550 and 980nm excitations

Up-conversion luminescence, temperature sensing properties and laser-induced heating effect of Er3+/Yb3+ co-doped YNbO4 phosphors under 1550 nm excitation

“…Among trivalent RE ions, Er 3+ is one of the most preferable RE ions for UC luminescence due to its uniform energy level distribution and proper energy distance between some metastable energy levels, which allows Er 3+ to be effectively excited by different laser wavelengths, such as 800, 980 and 1550 nm 7 . Moreover, Er 3+ is expected as an effective temperature sensing unit with high temperature sensing sensitivity based on its two thermally coupled emitting energy levels 2 H 11/2 and 4 S 3/2 , whose energy distance is about 770 cm −1  8,9 .…”

Up-Conversion Luminescence and C-Band Laser in Er3+-Doped Fluorozirconate Glass Microsphere Resonator

“…The ions then relax to the 4 I 13/2 level after which further excitation from the pump lifts the ion to the 4 F 9/2 level. The Er 3+ ions in the 4 I 11/2 level continue absorbing 980 nm laser and are excited to 2 H 11/2 , resulting in an excited state absorption (ESA) [26]. Ions with electrons located in the upper energy levels can relax directly back to the ground state.…”

“…ZrF 4 -BaF 2 -YF 3 -AlF 3 (ZBYA) fluorozirconate glasses have very attractive characteristics which favour their use in lasers including low phonon energy (∼580 cm −1 ), a wide transmission window and better performance in terms of resistance to moisture compared with conventional ZBLAN glass [25]. The luminescent properties of Er 3+ doped ZBYA glass have been extensively studied, indicating that ZBYA glass is a potential candidate for use as a visible to infrared range laser [26]- [28]. However, it remains difficult to fabricate low-loss optical fiber using ZBYA glass.…”

Mechanisms and absolute quantum yield of upconversion luminescence of fluoride phosphors

“…Er 3þ -doped phosphors are demonstrated efficient UCL upon excitation of different infrared energy levels of Er 3þ ions. At present, a large number of papers are devoted to the study of UCL of Er 3þ -doped fluoride and oxide phosphors upon excitation by laser radiation at about 980 nm [15][16][17][18][19][20][21][22] . UCL of SrF 2 :Er powders prepared by combustion synthesis ions was demonstrated upon excitation of the 4 I 11∕2 level of Er 3þ ions by Rakov [15] .…”

“…From literature it is known that excited-state absorption (ESA), energy transfer UC (ETU), and cooperative processes (CPs) are dominated mechanisms of UCL in Er 3þ -doped materials upon excitation of the 4 I 11∕2 level [15][16][17][18][19]21,22,28,29] . We recorded the rise and decay luminescence of Er 3þ ions from 4 G 11∕2 ð379 nmÞ, 2 H 9∕2 ð407 nmÞ, 4 F 5∕2 ð449 nmÞ, 4 F 7∕2 ð486 nmÞ, 2 H 11∕2 ð521 nmÞ, 4 S 3∕2 ð548 nmÞ, and 4 F 9∕2 ð668 nmÞ levels upon excitation of the 4 I 11∕2 level.…”