2 μm emission properties and nonresonant energy transfer of Er3+ and Ho3+ codoped silicate glasses

Abstract

2.0 μm emission properties of Er3+/Ho3+ codoped silicate glasses were investigated pumped by 980 nm LD. Absorption spectra were determined. Intense mid-infrared emissions near 2 μm are observed. The spectral components of the 2 μm fluorescence band were analyzed and an equivalent model of four-level system was proposed to describe broadband 2 μm emission. Low OH− absorption coefficient (0.23 cm−1), high fluorescence lifetime (2.95 ms) and large emission cross section (5.61 × 10−21 cm2) corresponding to Ho3+: 5I7→5I8 transition were obtained from the prepared glass. Additionally, energy transfer efficiency from the Er3+: 4I13/2 to the Ho3+: 5I7 level can reach as high as 85.9% at 0.75 mol% Ho2O3 doping concentration. Energy transfer microscopic parameters (CDA) via the host-assisted spectral overlap function were also calculated to elucidate the observed 2 μm emissions in detail. Moreover, the rate equation model between Er3+ and Ho3+ ions was developed to elucidate 2 μm fluorescence behaviors with the change of Ho3+ concentration. All results reveal that Er3+/Ho3+ codoped silicate glass is a promising material for improving the Ho3+ 2.0 μm fiber laser performance.

Fluoroindate Glass Co-Doped with Yb3+/Ho3+ as a 2.85 μm Luminescent Source for MID-IR Sensing

“…It can be seen that the shape of the luminescence band slightly changes after increasing the Ho 3+ content. It was presented in the literature that the four Stark emission bands, an equivalent model of four-level system for describing the 2 μm fluorescence band, can be used [ 38 ]. The four Stark emission bands centered at 1915, 1965, 2026, and 2078 nm can be distinguished.…”

“…The four Stark emission bands centered at 1915, 1965, 2026, and 2078 nm can be distinguished. In the fabricated fluoroindate glasses, the I 2078nm /I 1965nm intensity ratio increases upon increasing the Ho 3+ content, which also influences the FWHM ( Figure 2 b) [ 38 ].…”

“…A smaller distance between the donor and acceptor ions lea the efficient energy transfer from the excited 2 F5/2 energy level of ytterbium. It can be that the shape of the luminescence band slightly changes after increasing the Ho 3+ con It was presented in the literature that the four Stark emission bands, an equivalent m of four-level system for describing the 2 μm fluorescence band, can be used [38]. The Stark emission bands centered at 1915, 1965, 2026, and 2078 nm can be distinguishe the fabricated fluoroindate glasses, the I2078nm/I1965nm intensity ratio increases upon inc ing the Ho 3+ content, which also influences the FWHM (Figure 2b) [38].…”

Optical property evaluation of thoria doped with heavier rare‐earth oxides LnO1.5 (Ln = Er3+, Ho3+, Tm3+, and Yb3+)

“…UV‐visible spectra of doped and codoped samples are presented in Figure . For Ho 3+ (5 mol%)‐doped thoria sample, in addition to strong absorption band at 220‐230 nm (due to ligand to metal charge transfer (LMCT) transition), additional absorptions at 361, 418, 454, 483, 538, and 642 nm from the intraconfigurational f‐f transitions of Ho 3+ ‐ion ( 4 I 8 (ground state) to 4 G 9/2 , 5 G 5 , 5 G 6 , 5 F 3 , 5 S 2 (and 5 F 4 ), and 5 F 5 (excited states)) were seen . Similarly, transitions of Er 3+ ‐ions from 4 I 15/2 (ground state) to 4 G 11/2 , 4 F 7/2 , 2 H 11/2 , 4 S 3/2 , 4 F 9/2 , 4 I 9/2 , and 4 I 11/2 (excited states) appeared at 377, 487, 519, 546, 650, 795, and 972 nm in the UV‐visible spectrum of Er 3+ ‐doped thoria sample .…”

Effect of the Addition of Pb3O4 and TiO2 on the Optical Properties of Er3+/Yb3+:TeO2–WO3 Glasses

“…The HMT glasses and various crystalline nanomaterials doped with RE ions have great potential applications in the field of photonics, biomedical and home appliances, etc. 4,6−10…”