Fluorescence Branching Ratios Research Articles

Growth and spectral properties of Er3+/Yb3+/Ce3+:YPO4 crystal

Er3+/Yb3+/Ce3+ tir-doped YPO4 crystals were successfully synthesized by high temperature solution method with Pb2P2O7 as flux. The growth, structures and spectral characterizations, including polarization absorption spectra, polarization fluorescence spectra and lifetime, were systematically discussed. It has broad absorption band around 973 nm with a full width at half maximum of 20.76 nm and 14.71 nm for π- and σ-polarizations, respectively, which is suitable for efficient pumping of InGaAs laser diodes. Based on J-O theory, spectral parameters such as oscillator strength, line strength, J-O intensity, fluorescence branching ratio, spontaneous transition rate and radiation lifetime were calculated systematically. In the polarization fluorescence spectra, four strong emission peaks were observed at 1505, 1537, 1561 and 1586 nm. The results show that Er3+/Yb3+/Ce3+:YPO4 crystal may be a promising laser crystal suitable for 1.5–1.6 μm.

Analysis of spectroscopic characteristics of Sm3+ ions doped gallium silicate glasses for orange-red LEDs

In this work, a variety of Sm3+ ions doped gallium silicate glasses have been made using the conventional melt quenching procedure, and characterized by X-ray diffraction, absorption spectrum, fluorescence spectrum, fluorescence decay curves, respectively. The density of the glass increases with the increase of the concentration of Sm3+ ions, and XRD shows that the samples are all amorphous glasses. Absorption spectra were used to determine the J-O intensity parameters (Ωλ, λ = 2, 4, 6), as well as the radiation transition probability(A), fluorescence branching ratio(βr), and radiation lifetime(τr) of Sm3+ ions at the 4G5/2 energy level. Under 403 nm excitation, the emission spectra show obvious emission peaks at 602 nm and 649 nm, corresponding to 4G5/2 → 6H7/2 and 4G5/2 → 6H9/2 transitions respectively. The B3 glass sample has the largest emission cross section(σem) at the 4G5/2 → 6H7/2 transition, with σem = 11.40 × 10−22 cm2. The color coordinates, color purity and color temperature values of all samples were calculated. The color purity of all samples varied in the range of 96.20%–99.14 %, with the relevant samples separating in the orange-red light region. The experimental results indicate that the glass samples have a potential application prospect in the field of orange-red LEDs.

First Achievement of Yellow Laser Operation in Dy3+-Doped Borate Crystals.

Continuous-wave (CW) yellow lasers have been demonstrated successfully by using a GaN laser-diode (LD) pumping in borate crystals for the first time. The Dy3+:GdMgB5O10 (Dy:GMB) crystal with dimensions up to 33 × 19 × 15 mm3 is grown by the top-seeded solution growth method, and the polarized spectroscopic properties are investigated systematically at room temperature. The line strengths, Judd-Ofelt (J-O) intensity, spontaneous transition rates, fluorescence branching ratios, and radiative lifetimes are calculated in detail by the Judd-Ofelt theory. Under direct pumping of 452 nm LD, a compact continuous-wave yellow laser with a maximum output power of 628 mW and laser wavelength of 581 nm is generated based on a Y-cut Dy:GMB crystal. To our knowledge, it is not only the highest output power for yellow laser obtained in Dy3+-doped crystals but also the first yellow laser operation achieved by borate crystals under direct LD pumping. The results reveal that the Dy:GMB crystal is an optical material with important application prospects in yellow laser.

Characterization and Properties of ZnO:Nd<sup>3+</sup> Nanomaterial Synthesized by Chemical Synthesis Method

Nd3+ ion-doped ZnO nanomaterial was prepared using chemical synthesis method and its fluorescence spectra have been investigated at room temperature. From SEM images of the synthesized ZnO: Nd3+ nanoparticles it is observed that an increase in concentration of Nd3+ ions leading to the decrease in the particle size. Nearly hexagonal shapes for the dark spots in the SAED images indicate that the ZnO nanoparticles are almost hexagonal. The oscillator strengths leading to 4f ↔ 4f transitions are characterized by different Judd-Ofelt intensity parameters Ωλ (λ = 2, 4 and 6). These Ωλ parameters along with the fluorescence data and various radiative properties viz., spontaneous emission probability (A), radiative life time (t), fluorescence branching ratio (b) and stimulated emission cross-section (sp) were evaluated and compared with the reported values. The values of these parameters indicate that the observed transitions 4F3/2 → 4I11/2, 4F3/2 → 4I13/2 and 4F3/2 → 4I15/2 can be considered to be good laser transitions in the near infrared region for different optoelectronic and spintronic uses.

Luminescence properties and Judd-Ofelt analysis of Tb3+ doped Sr2YTaO6 double perovskite phosphors for white LED applications.

A series of Tb3+-doped Sr2YTaO6 double perovskite phosphors (SYT:Tb3+) were synthesized using a conventional solid-state reaction method. A strong green emission was observed in the SYT:Tb3+ phosphors, and the optimal doping concentration of Tb3+ was confirmed to be 5 mol%. The electric dipole-dipole interaction was ascribed to be the main mechanism for the luminescence concentration quenching. Analysis of the concentration-dependent fluorescence decay confirmed that the self-generated quenching model holds for the dynamic process of Tb3+ decays in SYT. Furthermore, the internal quantum efficiencies, non-radiative transition rates, and energy transfer rates of the 5D4 level for the SYT:Tb3+ samples were estimated, respectively. The luminescence thermal stability of the sample was also evaluated based on the Arrhenius model. The chromaticity shift of the SYT:5 mol% Tb3+ phosphor was examined to be 0.013 when the sample temperature was increased from 303 to 483 K, thus indicating excellent chromaticity shifting resistance under high temperature conditions. Moreover, the Judd-Ofelt parameters were calculated from the emission spectra of SYT:Tb3+ to be Ω2 = 0.29 × 10-20, Ω4 = 0.45 × 10-20, and Ω6 = 0.72 × 10-20 cm2, respectively. The fluorescence branching ratios and radiative transition rates for the 5D4 level were calculated based on the obtained Judd-Ofelt parameters. Finally, a white light-emitting diode (LED) prototype was assembled using a 310 nm LED chip combined with a prepared green SYT:Tb3+ phosphor and two other commercial blue and red phosphors. The obtained warm white light exhibits good chromaticity coordinates (0.32, 0.32) and a high color rendering index of 96.1. Based on the above results, it can be known that the prepared SYT:Tb3+ phosphors have a potential application as green emitting phosphors in white LEDs.

Application of Judd–Ofelt theory in analyzing Dy: SrCaF4 single crystal

The optical properties of Dy:SrCaF4 crystal in the visible range are investigated. Judd-Ofelt intensity parameters are evaluated following the assignment of Stark levels of absorption bands. The absorption coefficient and absorption cross section are reported, together with the line strengths of several transitions from the ground state to excited state manifold, oscillator strength of the electric and magnetic dipoles moments (fed, fmd). The emission wavelength (λem), calculated fluorescence branching ratios (βR), radiative emission probabilities (AR), total radiative emission probability (Ar) and radiative lifetime (τR) of Dy3+ in CaSrF4 crystal are investigated for the transitions from energy levels 4F9/2 (474 nm), 4I15/2 (452 nm), 6P5/2 (364 nm) and 6P7/2 (348 nm) to related sublevels. Dy:CaSrF4 crystal is a promising gain medium for a continuous wave or tunable solid state visible micro-laser under the pump wavelength of 348 nm, 364 nm and 474 nm.

Peculiar β-Li2TiO3: Eu3+ red light emitting dominated by electric dipole transition: Asymmetric lattice point regulation and luminescence performance

In order to obtain red phosphor with high color purity, β-Li2TiO3: Eu3+ dominated by electric dipole transition was prepared by the hydrothermal method. Eu3+ doping concentration (< 0.5 mol%) and calcination time (> 12 h) can regulate the phase purity, supercell development, asymmetric lattice point configuration and the luminescence performance. Under excitation at 394 nm, β-Li2TiO3: Eu3+ emits narrow band 618 nm red light due to that Eu3+ replaces Li+ at the relatively active Li1 position, and the 5D0 → 7F2 electric dipole transition dominates. Calcined at 600 °C for 36 h with Eu3+ doped concentration of 0.5 mol%, the luminescence performance of β-Li2TiO3: Eu3+ is superior, of which the lifetime is 0.64 ms, the color coordinates x = 0.63, y = 0.37, the color temperature of 987 K, the color rendering index of 82, and the red color purity of 99.7%. The electric dipole transition line intensity parameters Ω2 and Ω4 are 8.01 × 10−20 cm2 and 0.62 × 10−20 cm2, respectively, yielding Ω2/Ω4 of 12.9. The fluorescence branch ratio of 5D0 → 7F2 is 82.9%, and the quantum efficiency can reach 92%, which is superior within similar materials.

Benefit of Tb3+ ions to the spectral properties of Dy3+/Tb3+:CaYAlO4 crystal for use in yellow laser

Single crystals of Dy3+ single-doped and Dy3+/Tb3+ co-doped CaYAlO4 are grown and analyzed. In comparison to Dy3+:CaYAlO4, the absorption cross sections around 453 nm and emission cross section at 582 nm acquired a growth after the incorporation of Tb3+. The fluorescence lifetimes of Dy3+:4F9/2 upper and Dy3+:6H13/2 lower laser levels for 582 yellow emission fall from 0.293 ms to 0.070 ms–0.285 ms and 0.018 ms, respectively. The fluorescence branching ratios of yellow emission at 582 nm are 49.2% and 50.733% for Dy3+:CaYAlO4 and Dy3+/Tb3+:CaYAlO4 crystals, respectively. Deactivation effect of Tb3+ ions as well as the energy transfer mechanism in Dy3+/Tb3+:CaYAlO4 crystal are discussed in detail, and the temperature dependent spectra of the two crystals are also studied as well. Those results indicate that the introduction of deactivation ion Tb3+ can be beneficial for achieving an enhanced yellow emission in Dy3+/Tb3+:CaYAlO4.

Optical characterization of Sm3+ doped phosphate glasses for potential orange laser applications

Undoped and Sm3+doped 45P2O5–45Na2O–2Al2O3–8BaO glasses were synthesized by the melt-quenching technique. The glass structure and luminescence properties were investigated by using Raman spectroscopy, scanning electron microscopy (SEM), spectroscopic ellipsometry, Judd-Ofelt theory and photoluminescence. Electron microscopy showed the homogeneity of samples. Raman spectroscopy revealed that the overall structure of the glass was unaffected by the doping of Sm3+ and ellipsometry was used to measure the optical constants. Judd-Ofelt (JO) analysis was performed on the absorption bands of Sm3+ (4f5) and the three phenomenological parameters (Ω2, Ω4, and Ω6) were computed and then used to determine radiative properties such as the radiative transition probability (Ar), the fluorescent branching ratio (βr), the stimulated emission cross-section (σe) and the radiative lifetime (τrad). Photoluminescence (PL) spectrum showed the typical four transitions of Sm3+ at wavelengths of 564, 600, 645 and 703 nm corresponding to 4G5/2 → 6H5/2, 6H7/2, 6H9/2 and 6H11/2, respectively. The spectroscopic quality factors Ω4/Ω6, the predicted lifetime (τrad) calculated using the JO method and the experimentally lifetime (τexp) for the 4G5/2 level were calculated and discussed. The glass color purity is as high as 98%, which makes it a potential candidate for laser emission.

Spectral properties and theoretical analysis of Dy3+:KGd(WO4)2 crystals in the visible wavelength band

Yellow laser has been widely applied in various fields such as biomedicine, optical communication technology and chip processing. This study focuses on the preparation and characterization of a 3 at.% Dy3+:KGd(WO4)2 crystal. The crystal was grown by the top-seeded solution growth method. The absorption spectrum, excitation spectrum, emission spectrum, and fluorescence decay curve were measured at room temperature, and the fluorescence properties of the crystal in the yellow region were explored. Analysis of the absorption spectrum revealed an absorption cross-section σabs of 4.81 × 10−21 cm2 at 453 nm (E//Y), corresponding to the 6H15/2 → 4I15/2 transition. Utilizing the Judd-Ofelt theory, the J-O intensity parameters Ωt, radiative transition probability, fluorescence branching ratio, and radiative lifetime were calculated. The F-L theory was used to calculate the emission cross-section σem at 575 nm (E//Y), which was found to be 2.43 × 10−20 cm2, along with a fluorescence lifetime τf of 148.5 μs and a fluorescence quantum efficiency of 80.35% for 4F9/2. These findings suggest that Dy3+:KGd(WO4)2 crystal shows significant promise as a yellow laser material, with the potential to contribute to both commercial and scientific fields.

Fluorescence Study of Pr3+ Doped CdS Nanoparticles and its Applications in Sensors and Detectors.

Fluorescence spectra of Pr3+ doped CdS nanoparticles, synthesized by chemical precipitation method, have been recorded at room temperature. The synthesized particles are nearly spherical shaped and the grain size is decreased with the increase in Pr3+ concentration. The chemical identity of the nanoparticles was confirmed by EDAX spectrum, the absorption peaks was confirmed by FTIR spectrum and then the recorded values were compared with the CIE diagram. The oscillator strengths of the 4f ↔ 4I transitions are parameterized in terms of three phenomenological Judd-Ofelt intensity parameters Ωλ (λ = 2, 4 and 6). Using the fluorescence data and these Ωλ parameters, theoretical and experimental study of various radiative properties viz., spontaneous emission probability (A), radiative life time , fluorescence branching ratio and stimulated emission cross-section were evaluated. The values of these parameters indicate that 3P0→ 3H4 transition can be considered to be good laser transition in the visible colour region. Also, excitation with 493 nm, leads to similar blue regions. The synthesized Pr3+ doped CdS nanomaterials could be useful for sensing and detecting devices, particularly for temperature sensing measurement and bio-sensing detection.

Enhancing of 4F3/2 → 4I9/2 transition of Nd3+ doped BaO-Ga2O3– Al2O3–B2O3 glasses for near-infrared laser applications

Neodymium, Barium Gallium Aluminium Borate glasses having the composition of [35% B2O3 + 35% BaO + 15% Ga2O3 + (15-x)% Al2O3 + x% Nd2O3, (x = 0, 0.5, 1 and 2%)] were prepared using traditional melt quenching method. Physical properties such as refractive index (n), molar volume (VM), density (ρ), band-gap (Eg), and Urbach energy (ΔE) were measured and calculated. The results revealed that our glass has allowed indirect band-gap transitions and the addition of Nd3+ reduced the Eg energies from 3.24 to 3.01 eV. The Judd-Ofelt parameters were obtained using the least-square technique and they were used to compute the total radiative probability (At), radiative lifetime (τr), fluorescence branching ratio (Br), and quantum efficiency (η) for the meta-stable level 4F3/2. The glass system showed a high Spectroscopic factor (χ) ranging from 1.61 to 1.98. The Br showed that the 4F3/2 → 4I9/2 transition (883 nm) was enhanced at the expense of the 4F3/2 → 4I11/2 transition (1064 nm) and (4F3/2 → 4I13/2) transition (1342 nm). A relatively high quantum efficiency (η = 0.78) was noticed for our glass. Generally the spectroscopic properties and gain factor (γ) showed that the present glass system is a promising candidate for near-infrared laser applications (883 nm).

Growth and spectroscopic properties of a novel Tm3+-doped YSr3(PO4)3 disordered crystal

A novel Tm3+-doped YSr3(PO4)3 (Tm:YSP) crystal with a disordered crystal structure was grown by using the Czochralski pulling method. The single crystal growth, structure, absorption and emission spectra were systematically analyzed. The absorption bandwidth at ∼792 nm was found to be 21 nm, showing that the Tm:YSP crystal was very suitable for commercial laser diodes pumping of AlGaAs. Furthermore, the maximum emission cross section centering at 1835 nm was determined to be 0.86 × 10−20 cm2 with an emission bandwidth of 202 nm, which indicates the promising applications in the fields of ultrafast and tunable lasers. In addition, Spectroscopic parameters, containing Judd – Ofelt intensity, line strengths, radiative transition probabilities, fluorescence branching ratio and radiative lifetime, were analyzed by using the Judd – Ofelt theory. All above results showed that the Tm:YSP crystal with a disordered structure was a potential laser medium in the ⁓ 2 μm region.

Photo-physical properties of Pr (III) chelates of substituted nitrobenzoic acid and nitrophenols

Electronic absorption and emission spectra were recorded for chelates of Pr (III) with 2-hydroxy-4-nirobenzoic acid, 3-hydroxy-4-nitrobenzoic acid, 4-hydroxy-3-nitrobenzoic acid, 4-methyl-2-nitrophenol, 4-chloro-2-nitrophenol and 5-fluoro-2-nitrophenol in various M: L stoichiometry and for different pH. Intensity and energy of intraconfigurational 4fn transitions have been determined from the absorption spectra. The spectroscopic parameters like Slater-Condon (Fk), Racah (Ek), Lande (ζ4f) and Judd-Oflet parameters Ωλ (λ=2, 4, 6) have been computed using statistical method like partial regression method. The Judd-Oflet intensity parameters and fluorescence spectra have been used to calculate radiative life time (τ) of two excited states 3P0 and 1D2. From the fluorescence spectra of the chelates, effective line width (Δλeff) spontaneous emission probability (A), fluorescence branching ratio (β) and stimulated emission cross section (σ) have been determined for three optical transition 3P0-3H4, 3P0-3H5 and 1D2-3H4. Spectroscopic and intensity parameters were studied with respect to the ligand field symmetry and degree of bond covalency.

Growth and optical properties of a Sm3+, Eu3+ co-doped La2CaB10O19 crystal

Due to the excellent spectral properties, Eu3+-doped La2CaB10O19 (Eu3+:LCB) single crystals have shown promising prospect as a medium for laser radiation in the visible region. However, the weak absorption and emission intensities of Eu3+:LCB single crystals limit their laser application. Here, a Sm3+, Eu3+ co-doped La2CaB10O19 (Sm3+, Eu3+:LCB) crystal is grown to improve its optical performance. The intensity parameters, spontaneous transition probability, radiation lifetime and fluorescence branch ratio of the Sm3+, Eu3+:LCB crystal are studied with the Judd–Ofelt theory. Compared with an Eu3+-doped La2CaB10O19 (Eu3+:LCB) crystal, the Sm3+, Eu3+:LCB crystal exhibits higher absorption intensities and optical transition line strengths. Based on emission spectra, an energy transfer process from Sm3+ to Eu3+ ions in the Sm3+, Eu3+:LCB crystal is supposed. Fluorescence lifetimes for the Sm3+ and Sm3+→Eu3+ energy transfer process are calculated to be 1.698 ms and 3.648 ms, and energy transfer efficiency from Sm3+ to Eu3+ ions is calculated to be 13.7%. Compared with the Eu3+:LCB crystal, the emission intensity of the Sm3+, Eu3+:LCB crystal is doubled. Our work shows that the absorption and emission intensities of Eu3+:LCB crystals are significantly enhanced by co-doping with Sm3+ ions, which is conducive to their application for visible lasers.

Crystal growth and spectral properties of Eu3+-doped La2CaB10O19 single crystals

The invention and commercial application of InGaN/GaN-laser diodes have made it feasible to directly obtain the visible lasing radiation by pumping rare earth (RE) doped laser crystals. Hence searching for new laser crystals with efficient luminescence and applicable optical and physical properties in the visible range is an essential work. Here, the crystal growth and spectral properties of a series of large-size Eu3+ doped La2CaB10O19 (Eu3+-LCB) single crystals with the nominal atomic ratios of 3%, 7%, and 10% have been well studied. High-quality Eu3+-LCB single crystals with the size of 45 × 30 × 17 mm3, was grown by top-seeded solution growth (TSSG) method. The luminescence probe was employed as the tool to identify occupation sites, demonstrating that Eu3+ ions enter into La3+ sites first, then occupy Ca2+ sites after the nominal atomic ratio of Eu3+ ions exceeds 7%. Based on the absorption and emission spectra, the intensity parameters, spontaneous transition probability, radiation lifetime, and fluorescence branch ratio for Eu3+-LCB single crystals are studied with the Judd–Ofelt theory. From the transient spectra, the emission cross-section, fluorescence decay lifetime and luminescence quantum efficiency are deduced, which exhibit the maximum performance at the nominal atomic ratio of 7% Eu3+. Combining the luminescence probe and spectral properties, it can be concluded that Eu3+ doped crystals will have the best spectral properties when Eu3+ occupation at the single La3+ sites reaches the maximum in LCB single crystals, which may be universal for RE-doped crystal with two possible occupation sites. Besides, our work demonstrates that the 7% Eu3+-LCB single crystal may be a promising medium for laser radiation in the visible region in comparison with other Eu3+ doped single crystals.

Growth and spectral characteristic of Nd:CaMgSi2O6 crystal

A 0.56 at.% Nd:CaMgSi2O6 single crystal was successfully grown by the Czochralski method, the crystal’s polarized absorption spectra, fluorescence spectra and lifetime were investigated in details. Based on J-O theory, the line strengths, spontaneous transition rates, fluorescence branching ratios, and radiative lifetime were obtained. The strong and broad absorption band at around 803 nm matches well with the emission wavelength of AlGaAs laser diodes. There are three strong emission peaks located at 1055, 1081, and 1115 nm in fluorescence spectra. A laser output power of 0.262 W at 1055.25 nm with the slope efficiency of 16 % was obtained. The intense multi-wavelength emissions from the Nd: CaMgSi2O6 crystal indicate that such a crystal could be used advantageously for a multi-wavelength laser operation.

Study on the luminescence characteristics of Tb3+-doped TeO2-Bi2O3-BaF2 glass for blue-green laser emission

In this study, we prepared Tb3+-doped bismuth tellurite glasses by a high-temperature melting method. The matrix glass was characterized by higher thermal stability (ΔT = 102 °C) and lower maximum phonon energy (614 cm−1). Based on absorption spectra, Judd-Ofelt analysis revealed the spontaneous radiation transition probability (269.34 s−1) and fluorescence branching ratio (41.55%) of 5D4→7F5 transition. The luminescence peaks of the samples were located at 486 nm and 545 nm blue-green bands. Meanwhile, the luminescence intensity increased with the increase of Tb3+ concentration and reached the maximum at 4mol% Tb4O7. In addition, emission cross-section and gain coefficients were calculated in blue wavelength range, the maximum values were 2.01 × 10−22 cm−1 and 2.92 cm−1, respectively. Combining all the above results, Tb3+ doped bismuth tellurite glass had potential application value in the field of blue-green communication.

Broadband near-infrared luminescence property in Nd3+/Tm3+ co-doped tellurite glass

The near-infrared (NIR) band luminescent characteristics of tellurite glasses doped with Nd3+ and Tm3+ ions synthesized by melt-quenching conventional technology were explored. Differential scanning calorimetry (DSC) curves, Raman spectra, X-ray diffraction (XRD) patterns, absorption spectra, fluorescence spectra and fluorescence decay curves were measured. The XRD patterns demonstrated the amorphous state structural nature of the prepared glasses, the various structural units such as TeO4, TeO3+1, TeO3, BiO6, ZnO4, WO6 and WO4 were determined by Raman spectra, and DSC curves revealed the excellent thermal stability of glass host with ΔT of 150 °C. Based on the Judd-Ofelt theory, the transition probabilities and fluorescence branching ratios of the Nd3+:4F3/2→4I13/2 and Tm3+:3H4→3F4 transitions corresponding to 1.33 µm and 1.47 µm band emissions were (570.56 s−1, 10.94 %) and (320.75 s−1, 8.17 %), respectively. Under excitation at 808 nm laser diode (LD), the spectral overlap of these two bands produced a relatively flat and broadband fluorescence spectra located primarily at S + E band region with the full width at half maximum (FWHM) of 201 nm, which could provide an effective supplement to the present C + L-band of Er3+. The broadband luminescence mechanism of Nd3+ and Tm3+ ions and the interactions between them were discussed.

Study of the Optical Features of Tb3+:CaYAlO4 and Tb3+/Pr3+:CaYAlO4 Crystals for Visible Laser Applications

Single crystals of Tb3+ single-doped and Tb3+/Pr3+ co-doped CaYAlO4 were produced by the Czochralski method. The room-temperature polarized absorption spectra, emission spectra, and decay curves were recorded and analyzed in detail. The absorption cross-section around 487 nm was found to be 1.53 × 10−22 cm2 for the π polarization in the Tb3+:CaYAlO4 crystal and increased to 5.23 × 10−22 cm2 in the Tb3+/Pr3+:CaYAlO4 crystal. The spectroscopic parameters were calculated through the Judd–Ofelt theory. For the Tb3+:CaYAlO4 crystal, the emission bands of green light at 546 nm and yellow light at 587 nm had fluorescence branching ratios of 64.7% and 6.65% with cross-sections of 8.82 × 10−22 cm2 (σ-polarization) and 0.44 × 10−22 cm2 (π-polarization), respectively. The decay lifetimes of 5D4 multiplets were measured to be 1.41 ms and 1.1 ms for Tb3+:CaYAlO4 and Tb3+/Pr3+:CaYAlO4 crystals, respectively. The energy transfer mechanisms of Tb3+ and Pr3+ and their emission spectral intensities at different temperatures were analyzed. As the temperature increased, the luminescence intensity of the Tb3+:CaYAlO4 and Tb3+/Pr3+:CaYAlO4 crystals decreased almost linearly with the CIE coordinate variation, from (0.370, 0.621) to (0.343, 0.636) and from (0.345, 0.638) to (0.246, 0.698), respectively. The results indicate the potential of Tb3+:CaYAlO4 and Tb3+/Pr3+:CaYAlO4 crystals as visible laser materials with a wide temperature range.