Green Laser Applications Research Articles

The influence of Ho3+ ions on the optical and luminescence properties of fluoro borosilicate (SBNC) glasses for green laser applications

The holmium (Ho3+) ions-based fluoro borosilicate (SBNCHo) glasses have been prepared using the traditional melt quenching technique with varying concentrations of Ho3+ ions. Physical parameters were analyzed using x-ray diffraction, energy dispersive analysis of x-rays, fourier transform infrared spectroscopy, optical, luminescence, and Commission International de I'Eclairage (CIE) studies. Judd-Ofelt spectral intensity parameters were evaluated for SBNCHo_1.0 (Ω2 = 5.292 x 10-20 cm2, Ω4 = 3.062 x 10-20 cm2 and Ω6 = 3.376 x 10-20 cm2) glass, optical bandgaps were estimated using optical absorption studies. The Photoluminescence emission spectra were recorded for synthesized glasses with 452 nm excitation. The stimulated emission (σe = 1.40 x 10-20 cm2) for the intense green radiation (5S2 (5F4) → 5I8) was calculated. The lifetime decay profile was analyzed for all the synthesized glasses. From the CIE color coordinates of SBNCHo glasses, the color purity was estimated to be (SBNCHo_1.0 (98.6 %)). These results strongly support the applicability of SBNCHo_1.0 glass for green laser applications.

Effect of titania nano composite on structural and optical properties of Ho3+ doped silica glasses for green laser applications

Effect of titania nano composite on structural and optical properties of Ho3+ doped silica glasses for green laser applications

Luminescence properties of Tb3+ -doped sodium phosphate glasses for green laser and X-ray imaging application

Tb3+ doped sodium-gadolinium-aluminum-phosphate glass samples (PGNA) with chemical compositions 30Na2CO3:8Gd2O3:5Al2O3:(57- x)P2O5: x Tb4O7 (where x=0, 0.25, 0.5, 1.0, 2.0, 3.0, 4.0, and 5 mol. %) were manufactured by using adopting the conventional melt quenching technique. The PXRD study of the prepared samples was used to confirm the amorphous structure. FE-SEM, EDS, and FTIR studies were carried out to analyze the elemental and structural characteristics of synthesized glasses. The X-ray induced luminescence spectra were obtained at room temperature and the emission peak at 311 nm corresponding to Gd3+ transition was observed decreasing with the increase of Tb4O7 concentrations, while emission peak intensities corresponding to Tb3+ electronic transitions increased with the concentrations of Tb4O7. The results from the photoluminescence (PL) studies in the UV–Vis–NIR region showed the glasses emitting intense green light with the highest peak at 544 nm under excitations at 220, 272, and 311 nm. The PL emission intensities were found reasonably high under characteristic excitations of both Gd3+ and Tb3+, peaking at 380, 414, 437, 489, 544, 584, and 623 nm, which corresponding to 5D3→7F6,5D3→7F5, 5D3→7F4, 5D4→7F6, 5D4→7F5, 5D4→7F5, 5D4→7F4, 5D4→7F3 transitions, respectively. The decay time of Tb3+ ions has been observed to decrease when the concentration of Tb4O7 increases. The energy transfer from Gd3+ to Tb3+ was found increased with increasing of Tb3+ concentrations. The CIE 1931 chromaticity coordinates of Tb doped PGNA glasses were found to be in the green range, indicating a strong potential for green laser application. The results from X-ray imaging showed that Tb-doped glass scintillators promise of efficient and low-cost solution for X-ray imaging applications.

The role of co-dopant Ce3+ on the spectral properties of Dy3+ activated YAG single crystal for yellow green laser application

Ce3+ and Dy3+ co-doped Y3Al5O12 (abbr. as Ce, Dy: YAG) single crystal was grown by the Czochralski method. As compared with the absorption spectrum of Dy: YAG crystal, the synchronous doping of Ce3+ ions into Dy: YAG crystal resulted in a wide excitation band in the 425–500 nm region peaking around 447 nm owing to the 4f→5d transition of Ce3+ ions, and inhomogeneous broadening absorption with the full width at half maximum (FWHM) from 4 nm to 39 nm. Furthermore, due to the efficient energy transfer from Ce3+ to Dy3+ ions in YAG crystal, under 447 nm excitation Ce, Dy: YAG crystal showed intense and wide characteristic yellow green emission, whose intensity increased by 12.3 times and FWHM from 12 nm to 113 nm as compared with Dy: YAG crystal. The fluorescence lifetime of Dy3+: 4F9/2 level has increased from 693.1 μs to 2.062 ms. Based on the above results, Ce, Dy: YAG crystal would be an excellent candidate for the realization of yellow green waveband laser output.

Ho3+-activated calcium zinc silico-aluminate glass for 2 µm and 533 nm laser application

This study reports the synthesis and property analysis (thermal, mechanical, physical, and luminescence) of Ho3+ doped Calcium Zinc Silico-Aluminate glasses (CZSAHoy; y = 0.1, 0.4, 0.8, and 1.6 mol% ) which are prepared by melt quenching technique. All the synthesized glass samples show good thermal stability (ΔT=134–158 °C), elastic modulus (E = 110–115 GPa), and hardness (Hv=7.16–7.45 GPa) properties. The intensity of emission peaks at 2 µm and 553 nm is increased up to 0.8 mol% of Ho2O3 and beyond this concentration, quenching effect is dominated due to ion-ion interactions. By analyzing luminescence properties along with thermal and mechanical properties, the CZSAHo0.8 glass displays optimum properties. The broad emission bandwidth of 180 nm with high gain coefficient of 1.55 cm−1 and low pumping laser threshold (population inversion, p ≥ 0.4) for 2 µm emission from CZSAHo0.8 glass can be considered as suitable for fiber laser/amplifier application. Further, the high stimulated peak emission cross-section value of 6.59 × 10−21 cm2 and color purity (98.9%) of CZSAHo0.8 glass for 553 nm emission makes it suitable for green laser application.

The Effect of Alkali-Fluoride on the Photoluminescence Properties of Tb3+ Doped on Phosphate Glass Medium

The effect of alkali fluoride on the photoluminescence properties of Tb3+ doped on the phosphate glass was discovered. However, the composition of the glass samples were 20Li2O–10AlF3–69P2O5–1Tb2O3 (LAPTb) and 20Li2O–10AlF3–10NaF–59P2O5–1Tb2O3 (LANPTb). To study optical properties were examined through their absorption and luminescence spectra. Luminescence spectra were investigated by photoluminescence. Characteristic luminescence bands corresponding to electronic transitions of terbium ions (Tb3+) were detected under two direct excitations of Tb3+ ions. Upon 377 nm excitation, the glass samples were obtained transition terbium 5D4 → 7F5 at 544 nm showed a green laser. The decay time Tb3+ for the 5D4 level has been confirmed and the result was 2.865 ms and 2.982 ms corresponding to LAPTb was LANPTb, respectively. The green laser application has been investigated by a CIE-color-coordinates diagram with a color purity is ~73%.

Spectroscopic features of Tb3+ doped strontium zinc borate glasses for green laser applications

These days green laser is preferred as a flexible tool for welding direct bonded copper plates used in power electronics to improve electrification of automotive industry. As terbium is known for green emission, Tb3+ doped strontium zinc borate glasses are melt quenched. The broad hump in x-ray diffraction spectra revealed the amorphous nature. Structural modifications and stability of glasses was shown from fourier transform infrared spectra and differential thermal analysis traces. The Judd-Ofelt intensity parameters are calculated to realize the ligand environment among Tb3+ ions in host glass. The Tb3+ concentration dependent fluorescence properties in visible region and the non-radiative decay rates of 5D4→7F5 transition due to resonant energy transfer apart from intensity quenching of 5D3→7F5 transition in green region was studied. A strong peak registered at 542 nm for the transition 5D4→7F5 in the green region of emission spectra under the excitation of 378 nm. The radiative properties for the prominent luminescent transitions 4D5→7FJ (J=6,5,4,3) of Tb3+ ions are measured using Judd-Ofelt parameters. The values σe, βR,η (%), life- time decay and CIE co-ordinates for the transition 5D4→7F5 confirms that this transition is appropriate for potential green laser.

Erbium(III) ion-doped borate-based glasses for 1.53 μm broad band applications.

Novel erbium(III) ion-doped borate-based glasses (Er3+ :BCNF) by conventional melt-quenching technique were designed and synthesized. The glasses were characterized for their structural, vibrational and spectroscopic properties. The nephelauxetic ratio, bonding parameters, and Judd-Ofelt (JO) intensity parameters (Ωλ λ = 2, 4 and 6) were determined by using absorption spectrum of 1mol% Er2 O3 doped glass. These JO parameters were utilized to derive radiative properties for various excited states of erbium(III) ions. Emission cross-section for 4 I13/2 → 4 I15/2 transition of erbium(III) ions was computed through McCumber theory. The decay curves for (2 H11/2 , 4 S3/2 ) and 4 I13/2 levels were recorded and analysed. All the results of Er3+ :BCNF glasses revealed that the studied glasses are efficient and thermally stable and could be suitable for display devices, optical amplification and green laser applications.

High-concentration Er3+ ion singly doped GaTaO4 single crystal for promising all-solid-state green laser and solid-state lighting applications

A Er:GdTaO4 single crystal was grown by Cz method. The results indicate that the crystal is promising for diode pumped green lasers and probably useful for solid-state lighting.

Spectral characteristics of Tb3+ doped ZnF2–K2O–Al2O3–B2O3 glasses for epoxy free tricolor w-LEDs and visible green laser applications

In the current work, a series of Zinc Potassium Alumino fluoroborate (ZKAlFB) glasses doped with different concentrations of Terbium ions (Tb3+) were synthesized by employing the melt-quench technique. The spectroscopic properties of the as-prepared glass samples were examined using characterization techniques like XRD, FT-IR, DSC, UV–vis–NIR absorption and emission to unlock their utility in photonic devices. Absorption spectral information was used to determine the nature of bonding between Tb3+ ions and its surrounding ligands. FT-IR spectral information recorded for an undoped glass has been used to understand various functional groups present in the as-prepared ZKAlFB glass. The DSC thermogram was used to estimate glass thermal stability (ΔT) and transition temperature (Tg) of the as-prepared ZKAlFB glass. The Judd-Ofelt (J-O) intensity parameters estimated from absorption spectral data are correlated with the emission spectral profiles to estimate radiative properties. The photoluminescence (PL) intensity of the as-prepared ZKAlFBTb glasses is found to be maximum for 1 mol% of Tb3+ ions and beyond decreases showing concentration quenching. Using PL spectral data, the CIE color coordinates, and Correlated Color Temperature (CCT) values were evaluated to understand the suitability of the as-prepared glasses for green color emitting photonic devices. The experimental lifetime values estimated from the decay profiles are decreasing with elevation in Tb3+ ion concentration due to energy transfer through the cross-relaxation process. Quantum efficiency (η), emission cross-section (σse), CIE and CCT values obtained for 1 mol% Tb3+ ions doped ZKAlFB glass demonstrates its superiority in fabricating epoxy free tricolor w-LEDs and visible green lasers.

Adjunctive Green Thermal Laser Photocoagulation for Treatment of Resistant Infectious Keratitis.

PurposeTo investigate the safety and efficacy of green thermal laser as an adjunctive therapy for the treatment of resistant infectious keratitis (IK) in the Delta region of Egypt.MethodsA retrospective case series of 150 patients, within a 4 year duration, with resistant IK, who failed to respond to specific medical treatment alone for 7 days, were included. They all received green thermal laser photocoagulation treatment to the cornea as an adjunctive to medical treatment.ResultsForty-eight women and 102 men were included in this study with a mean age of 46.2 ± 7.7 years. Common risk factors associated with IK included trauma by material of plant origin and contact lens wear. The mean duration of healing was 2.87 ± 0.7 weeks. A single session of green thermal laser application was adequate in 138 IK cases (92%), while 12 cases (8%) required an additional session a week later. Supplementary amniotic membrane transplantation (AMT) was required in 26 cases (17.3%). Two patients (1.3%) required tectonic keratoplasty for corneal perforation. The final corrected distance visual acuity (CDVA) was counting fingers (CF) or better in 78 patients (52%). No decrease of CDVA was reported throughout the study.ConclusionGreen thermal laser is a safe and effective adjunctive therapy for the treatment of resistant infectious keratitis.

Spectroscopic study of Er3+ doped borate glass system for green emission device, NIR laser, and optical amplifier applications

The 10BaO–20ZnO–20LiF-(50-x)B2O3-xEr2O3 (x = 0, 0.1, 0.5, 0.7, and 1.0 mol %) glass system was studied for green emission device, NIR laser, and optical amplifier applications. The impact of Er3+ doping was assessed through structural, optical, and thermal properties. The Er3+ ions behaved as network modifiers and decreased the network rigidity by the transformation of [BO4]→[BO3] and Non-Bridging Oxygens. This was consistent with the decrease in the glass transition temperature. Ten absorption peaks of Er3+ ion equivalent to transitions from 4I15/2 to various excited levels were quantified through their oscillator strengths. Through broadband impedance spectroscopy, the insulating property of the glass system was authenticated by the persistence of dc-conductivity in the order of 10−10 Scm−1 up to 523 K. With 378 nm excitation, a violet emission (2H9/2→4I15/2) and two intense green emissions (2H11/2→4I15/2, 4S3/2→4I15/2) were noticed. The NIR emission (4I13/2→4I15/2) was observed at 1531 nm with 378 and 980 nm excitations and the corresponding decay curves were recorded. The Inokuti-Hirayama model indicated the increase in the energy transfer and reduction in critical distance amid the Er3+ ions with doping leading to energy migration through cross-relaxations and lifetime quenching. The laser parameters were determined from Fuchtbauer-Ladenburg theory. The color coordinates of the samples were lying in the green region, with purity >89% and CCT >6000 K. The gain coefficient from McCumber theory was positive for a population inversion >50%, with a wide gain between 1460 and 1565 nm, extending the application of the glass system as an optical amplifier in the S + C communication window.

A novel Er3+ ions doped zirconium magnesium borate glass with very high quantum efficiency for green laser and optical amplifier applications

A potential new series of Er3+ ions doped zirconium magnesium borate (ZMB) glasses have been prepared by conventional melt quenching method. Aperiodic nature of the glasses was confirmed by X-ray diffraction analysis. SEM image shows the nonappearance of any defined shape or structure which confirms the amorphous nature. The Refractive index of the glasses increases in the value from 1.611 to 1.671 with increase of Er3+ ion concentration. The optical absorption, excitation and emission spectra of the Er3+ doped glasses were recorded from ultraviolet (UV) to visible (Vis) and near infra-red (NIR) range with different equipment's. The oscillator strength and JO intensity parameter (Ω2, Ω4 and Ω6) were calculated from the absorption spectra. The photoluminescence spectra of the present glasses exhibit two emissions (2H11/2 → 4I15/2 and 4S3/2 → 4I15/2) bands in the visible region by exciting 491 nm and exhibit one emission (4I13/2 → 4I15/2) in the NIR region with the 980 nm as an excitation source. The experimental lifetime (τexp), FWHM, figure of merit (σPE × τexp), gain bandwidth (σPE × Δλeff) and stimulated emission cross-section (σPE) values have been calculated for all the present glasses for visible and NIR emission transition. The decay spectra measured for 4I13/2 → 4I15/2 transition shows single exponentials for all Er3+ ion concentrations of the glasses. CIE 1931 diagram shows the exact emission colour (green) of the prepared glasses. Correlated colour temperature points show along with the block body curve line and can be used for cold lighting purposes. From the all the results, it is observed that, 1ErZMB glass is more potential candidate for green laser, optical amplifier and designing of photonic devices.

Spectroscopic and luminescence properties of Ho3+ ions doped Barium Lead Alumino Fluoro Borate glasses for green laser applications

Optically transparent Barium Lead Alumino Fluoro Borate (BaPbAlFB) glasses doped with different concentrations of Ho3+ ions were prepared by using melt quench technique. Raman spectral studies were conducted to understand the structural groups present in the as prepared glasses at room temperature. Spectroscopic investigations such as optical absorption, excitation, emission and decay measurements were conducted to understand the visible photoluminescence (PL) and lasing potentialities of BaPbAlFB glasses. The bonding parameters (δ) estimated from the absorption spectral features were used to understand the nature of bonding between Ho3+ ions and the surrounding ligands. The Urbach energy values estimated from the absorption spectral data are used to verify the amorphous nature of the present glass system. The Judd-Ofelt (J-O) theory has been applied to the measured oscillator strengths of the absorption spectral features to estimate the best fit J-O parameters (Ωλ, λ = 2, 4, and 6) useful in evaluating various radiative parameters for the prominent fluorescent levels of Ho3+ ions in BaPbAlFB glasses. The experimental lifetimes (τexp) are found to be decreasing with increase in Ho3+ ion concentration owing to energy transfer. The quantum efficiency (η) of Ho3+ ions doped BaPbAlFB glasses were estimated by correlating the experimental lifetimes (τexp) with the radiative lifetimes (τR). The strong visible emission, large stimulated emission cross-section (σse), high branching ratio (βR) and relatively good quantum efficiency (η) obtained for 5S2→ 5I8 (green) transition of 1 mol% of Ho3+ ions doped BaPbAlFB glass reveals its suitability in designing and developing visible green lasers.

The impact of Er3+ ions on the spectroscopic scrutiny of Bismuth bariumtelluroborate glasses for display devices and 1.53 μm amplification

Er3+ incorporated Bismuth bariumtelluroborate [BTBxEr] glasses were synthesized using the composition, 20TeO2 + (30–x)B2O3 + 30BaO + 20Bi2O3 + xEr2O3, following the traditional melt quenching method. The bonding parameters were calculated using absorption spectra to analyze the dopant-host bonding nature. Ωλ (λ = 2,4,6) intensity parameters are determined from the oscillator strengths employing Judd-Ofelt (JO) theory for the estimation of the radiative parameters. Broad emission transition 4I13/2 → 4I15/2 were observed around 1530 nm, under 980 nm excitation which exhibits outstanding increased intensity with the Er3+ concentration of till it reaches 0.5 wt%. CIE chromaticity coordinates, CCT and Duv have determined to analyze the color of emission and the absorption quality of the glasses. Lifetime for the 4I13/2 excited (at 980 nm excitation) and 4S3/2 (at 488 nm excitation) levels of Er3+ ions were measured using decay measurements. Of all investigations, BTBEr glasses could be an apt material for the fabrication optical amplifiers, display devices and green laser applications.

Kinetics characterization and visible photoluminescence spectroscopy of an erbium-doped tellurite glass

This article aims to study the detailed thermal behavior, characterization of kinetics and the luminescence properties of TeO2–Li2O–ZnO–Nb2O5–Er2O3 glass system as a function of increasing Er2O3 (mol%). Kinetic parameters of the glass series have been studied by the data obtained from the differential scanning calorimetry (DSC) under non-isochronal circumstances at heating rates (β) 10, 15, 20 and 25 K min−1 using the continuous-heating technique. The glass thermal stability (ΔT), the thermal relaxation resistance (ΔS) and the glass stability parameter (KSP) have been calculated to state the applicability of using the glass in specific fields and applications. Activation energies of both the glass transition (Eg) and crystallization (Ec) processes were determined from the shift of the transition (Tg) and crystallization (Tc) temperatures with the different heating rates using Kissinger’s and Ozawa’s techniques. The kinetic Avrami number (order of the crystallization reaction) (n) was also calculated to define the mechanism of the crystallization process. Quantitative interpretation of the kinetic parameters (the relation between thermal and structural properties with changing the chemical composition) also has been provided. The luminescence properties showed that the glass with the least concentration of Er2O3 (0.5 mol %) exhibited the higher emission intensity which might be a suitable candidate for the green laser applications.

Effect of modifier oxides (SrO, Al2O3, ZnO, CdO, PbO and Bi2O3) on the luminescence properties of Er3+ doped telluroborate glasses for laser and optical amplifier applications

Er3+ ion (0.5 wt%) doped telluroborate glasses were prepared with various modifier oxides through melt quenching technique. The glass samples were labeled as TBSE, TBAE, TBZE, TBCE, TBPE and TBBE corresponding to SrO, Al2O3, ZnO, CdO, PbO and Bi2O3, respectively. The effect of modifier cations on the spectroscopic properties of Er3+ ions was analyzed through FTIR, optical absorption, photoluminescence and lifetime measurements. Presence of different vibrational groups and the structural changes caused by the incorporation of various modifier ions were identified via FTIR spectra. Bonding parameter (δ) values indicate the predominant ionic nature of Er–O bond in the prepared glasses. The Judd-Ofelt (JO) parameters follow the trend of Ω2 > Ω6 > Ω4 for TBSE, TBAE, TBCE and TBPE glasses whereas TBZE, TBBE glasses posses different order such as Ω2 > Ω4 > Ω6. The visible emission spectra (excitation at 379 nm) exhibit three emission bands centered at 531, 547 and 638 nm corresponding to 2H11/2→4I15/2, 4S3/2→4I15/2 and 4F9/2→4I15/2 transitions of the trivalent erbium ions. Among these emission bands, the green emission is quite intense. NIR luminescence spectra were recorded by exciting at 980 nm exhibit broad emission at 1550 nm (4I13/2→4I15/2 transition). Incorporation of different modifier cations reveals significant changes in the luminescence intensity and radiative parameters of the prepared glasses. Radiative parameters such as transition probability, effective bandwidth, stimulated emission cross-section and branching ratio have been estimated for 4S3/2→4I15/2 and 4I13/2→4I15/2 transitions. Emission cross-section (σe) and the gain coefficient (G) for the 4I13/2→4I15/2 transition have been estimated through McCumber theory. Decay profile of 4S3/2 and 4I13/2 excited states of Er3+ ion is of bi-exponential nature. It indicates that more than one relaxation mechanisms are operating in decay of the excited state of Er3+ ions. Glasses containing bismuth (TBBE) are endowed with higher stimulated emission cross-section (71.74 × 10–22 cm2) and gain bandwidth product (638 × 10–28 cm3) for 4I13/2→4I15/2 transition. The present study suggests the Er3+ ions doped telluroborate glass with bismuth cation to be best candidate for green laser and broadband optical amplifier applications.

Synthesis of luminescent terbium-thenoyltriflouroacetone MOF nanorods for green laser application

The metalorganic frameworks (MOFs) with lanthanides ions offer great potential in the optical area because can provide properties of flexibility, low density, low-cost methods of synthesis, and insolubility in water, which give them an advantage over traditional phosphors. In this study, a thenoyltriflouroacetone ligand (TTA) with a Tb3+ MOF was synthesized (Tb = 10 and 50% mol) and its structural and luminescent properties were analyzed. The metalorganic compound was generated in a simple one-pot reaction from terbium nitrate and 2-thenoyltrifluoroacetone precursors at room temperature. By means of FTIR, it was confirmed the presence of carbon groups, which made possible the terbium ion chelation, and also the Tb-O bonds vibration modes. 1HNMR results confirm that the complex with 10% mol of Tb3+ contains three coordinates molecules of TTA and two waters molecules. The powders exhibit rod-like morphology with size about 170 nm of diameter and a length about 2 μm; the rod-like nature of powders was confirmed by SEM and TEM analyses. By XRD it was concluded that at higher terbium concentration (TTA-50Tb sample) higher the crystallite size and crystallinity, in fact the TTA-10Tb sample shows a partial-amorphous nature. By photoluminescence analyses, the 5D4→7FJ (J = 3, 4, 5 and 6) emissions were recorded for both synthesized samples (λexc = 376 nm). Furthermore, it was observed that the emission intensity was enhanced in a factor of 3.5 for the TTA-50Tb. The energy transfer efficiency from TTA to Tb3+ (antenna effect) was 0.984 for TTA-10Tb and 0.993 for TTA-50Tb. Decay time analyses indicate effective lifetime of 1.45 and 1.60 m s for the samples doped at 10 and 50%, respectively, indicating that the forbidden transition rules are stronger at higher crystallinity. The integrated intensities of the 5D4→7F5 (green at 541 nm) and 5D4→7F6 (blue at 486 nm) emissions and their intensity ratios IG/IB upon 376 nm excitation have been evaluated for TTA-10Tb andTTA-50Tb samples. The CIE1931 color of the MOFs excited at 376 nm attains a higher green color purity by increasing the terbium concentration. This is in concordance with the increased IG/IB ratio up for the TTA-10Tb and TTA-50Tb samples. Thus, the TTA-50Tb sample exhibits a green color purity of 67.94% with chromaticity coordinates (0.30, 0.57), being very close to those (0.29, 0.60) of European Broadcasting Union illuminant green. This interesting feature of the TTA-50Tb sample, together with an experimental branching ratio of 61.3% for the 5D4 → 7F5 green emission, highlights its capability as solid state green laser pumped by GaN (376 nm) LEDs.

Investigation of Luminescence Properties of Tb3+ Ions In Gadolinium Borogermanate Glasses For Green Laser Application

30B2O3-40GeO2-(30-x)Gd2O3-xTb2O3 (x=1,2,3,5 ve 7 % mol) kompozisyonuna sahip cam sistemleri eritmetavlama yöntemi ile sentezlenmiştir. Hazırlanan camların optik ve lüminesans özellikleri soğurma, fotolüminesansve bozunma zamanı ölçümleri ile incelenmiştir. Tb+3 katkılı borogermanat camlarının 378 nm uyarma altında eldeedilen fotolüminesans spektrumları yeşil bölgede şiddetli yayınlanma (5D4→7FJ , J = 3,4,5 ve 6) ve mavi bölgedezayıf yayınlanma (5D3→7FJ , J = 3,4 ve 5) piklerinden oluşmaktadır. Bunların arasında en şiddetli 5D4→7F5 (541 nm)geçişi yeşil yayınlanma göstermektedir. x=5 katkı miktarından sonra konsantrasyon baskılanması gözlenmiştir.5D4→7F5 ve 5D3→7F4 yayınlanma piklerinin alanlarının oranı olan yeşil-mavi değerleri (G/B) Tb+3 iyon konsantrasyonununfonksiyonu olarak elde edilmiştir. Tb+3 iyonunun 5D4→7F5 geçişinin bozunma zamanı 1.801 ms olarakbulunmuştur. Hazırlanan camların elde edilen renk koordinatları CIE diyagramının yeşil bölgesinde yer almaktadır.

Luminescent properties of Tb3+- doped TeO2-WO3-GeO2 glasses for green laser applications

Different concentrations of Tb3+ -doped oxyfluoro tellurite (TWGTb) glasses were prepared by conventional melt quenching technique and characterized for green laser applications. The Judd-Ofelt theory was applied to evaluate various spectroscopic and radiative parameters. The TWGTb glasses exhibit 5D3 → 7F5-3 and 5D4 → 7F6-0 transitions when excited at 316 nm radiation. The variation of intensity of 5D4 → 7F5 (Green) and 5D3 → 7F4 (Blue) transitions and the green to blue (IG/IB) intensity ratios were studied as a function of Tb3+ ions concentration. The laser characteristic parameters such as effective bandwidth (Δλeff), stimulated emission cross-section (σe), gain bandwidth (σe × Δλeff) and optical gain (σe × τR) were determined using the three phenomenological Judd-Ofelt intensity parameters. The fluorescence decay profiles of 5D4 metastable level exhibit single-exponential nature for all the samples. Based on the experimental results we suggest that the 1.0 mol% of Tb3+ -doped TWGTb glass could be a suitable laser host material to emit intense green luminescence at 545 nm.