Search

For the near-infrared emission, Er3+ and Er3+/Yb3+ co-activated borate based glass hosts were synthesized by the method of melting andquenching. The emission intensity was maximum for 0.5 mol% Er3+ singly activated glass in the near-infrared (NIR) region covering the telecommunication window. The 2 mol% of Yb3+ co-doping enhanced the emission gain cross-section of the glass by two times contrast to 0.5 mol% Er3+ loaded glass. This enhancement shifted to lower spectral regions when P increased from 0 to 1. The effect of Yb3+ loading on the gain cross-section of the Er3+ co-activated glasses was analyzed using the McCumber theory. The results showed that the 0.5Er2Yb glass has a flat gain in the range of 1460–1640 nm, this suggest a lower pump threshold is enough to perform the laser functioning of a 1530 nm band and optical window of telecommunication applications. [ABSTRACT FROM AUTHOR]

Gamma irradiation effect on absorption, photoluminescence (PL), and nonlinear optical (NLO) features of Eu3+ doped heavy metal borate glasses was studied and elucidated in detail. With blue light excitation, the emission intensity of Eu3+ doped glass was monitored with respect to irradiated dose. The PL intensity of the glasses was reduced with a raise in gamma dose rate because of the formation of colour centres. The quality of the emission colour of the pre- and post-irradiated glasses was analysed using 1931 CIE system. The Nonlinear Optical (NLO) features were examined by the Z–scan technique in the near–infrared spectral region and using femtosecond pulse excitation. The NLO attributes were enhanced with increase gamma irradiation dose. These enhancements are ascribed to the development of defects and non–bridging oxygens when irradiated with gamma radiation. The enhancement of NLO coefficients with gamma irradiation dose suggest the high dose irradiated glasses are useful for photonic device applications, particularly for optical limiters. • Influence of gamma irradiation on the PL and NLO properties of Eu3+ doped heavy metal borate glasses was investigated. • PL properties were evaluated under blue light excitation. • PL intensity of the glasses was reduced with a raise in gamma dose rate. • NLO attributes were enhanced with increase gamma irradiation dose. [ABSTRACT FROM AUTHOR]

Photonic vitreous materials with high optical nonlinearities and fast response times are beneficial for designing next generation nonlinear photonic devices. Herein, large concentration of heavy metal oxide (PbO and Bi 2 O 3) containing borate glasses activated with different Eu3+ concentrations have been designed through the melt quench technique. The non-linear optical (NLO) attributes such as nonlinear optical absorption and refractions were ascertained by utilizing the open aperture (OA) and closed aperture (CA) Z-scan techniques respectively in the spectral regions of 750–1000 nm using femtosecond laser pulses. The OA and CA Z-scan profiles demonstrated a reverse saturable absorption (RSA) nonlinearity (ascribed to two-photon absorption) and a positive nonlinear refraction nonlinearity (attributed to self-focusing effect) respectively. The NLO coefficients such as α 2 , n 2 and χ(3) values were improved with respect to Eu3+ content in the glasses composition due to non-bridging oxygen and hyperpolarizability of Eu3+ ions. The NLO studies suggested that the examined glasses could be constructive materials for NLO device utilizations in the near infrared spectral regime. Image 1 • Effect of Eu3+ ions on optical nonlinearities of PbO and Bi 2 O 3 containing borate glasses was investigated and analysed. • Z-scan profiles of studied glasses showed a positive optical nonlinearities at near–infrared spectral regions. • Non–linear optical coefficients were exhibited an increase trend with respect to Eu3+ content. • Optical non–linear results clearly suggest the examined glasses are beneficial for optical limiting applications. [ABSTRACT FROM AUTHOR]

Herein, heavy metal borate glasses activated with different concertation of Eu 2 O 3 were prepared via the melt quench method. The Eu3+ concentration effect on photoluminescence (PL) properties of prepared glasses was investigated and discussed in detail to understand their utility in solid-state lighting and other photonic applications. The present work explains the suitability of two heavy metal oxides such as PbO and Bi 2 O 3 for Eu 2 O 3 doping to develop the glassy materials for photonic applications. The PL intensity was increased with an increase in Eu3+ content in PbO framed borate glasses while in Bi 2 O 3 containing borate glasses the PL intensity was decreased at higher concentration due to concentration quenching. The Judd–Ofelt parameters and the radiative properties suggest the heavy metal borate glass hosts activated with 1 mol % of Eu3+ were potential materials for red light-emitting devices under blue light excitations. The Lifetime values of the PbO framed glasses were greater compared to Bi 2 O 3 framed borate glasses which suggest the borate glass host containing high PbO content is more precisely suitable than Bi 2 O 3 containing borate glass for solid-state lighting applications under blue light excitation. Image 1 • Photoluminescence properties of Eu3+ ions in PbO and Bi 2 O 3 containing borate glasses were investigated. • The PbO containing glasses activated with 1 mol % of Eu 2 O 3 were exhibited improved spectroscopic and luminescence properties. • Studies suggest the PbO containing glasses are beneficial for solid state lighting application under blue light excitation. [ABSTRACT FROM AUTHOR]

Efficacy of tri‒valent samarium ions concentration on the optical and third‒order nonlinear optical (NLO) properties of multicomponent cadmium alkali borate‒based glasses prepared by standard melting‒quenching method has been investigated in this work. The optical properties of cadmium alkali borate glass activated by rare-earth oxide (i.e., Sm 2 O 3) were carried out by using UV–Visible absorption spectroscopy at room temperature. Optical absorption peaks were obtained around 402 nm, 1076 nm, and 1078 nm wavelength. The Fourier transform infrared spectroscopy results revealed the existence of distinct borate units, in the structure of glasses used in the investigation. Z‒scan experiments in the near‒infrared (NIR) spectral regions utilizing the femtosecond (fs) laser pulses were used in order to evaluate the NLO parameters. The two‒photon absorption coefficient and the index of nonlinear refraction values improved significantly for 2 mol% of Sm 2 O 3. This endorses 2 mol% of Sm 2 O 3 encompassed glasses are beneficial for constructing the NLO devices assigned to perform in the NIR region. • Effect of Sm 2 O 3 on third‒order nonlinear optical properties of multicomponent borate‒based glass was studied. • CA Z‒scan patterns exhibited positive nonlinear refraction manifested to self‒focusing effect. • OA Z‒scan patterns confirms existence of RSA manifested to TPA. • Multicomponent borate‒based glass containing 2 mol % of Sm 2 O 3 exhibited large TPA and χ(3). [ABSTRACT FROM AUTHOR]

• Effect of Eu2O3 on PL properties was investigated and confirmed the optimize concentration. • Efficacy of Ag NPs on PL properties of optimized Eu2O3 activated glasses were investigated. • Role of Ag NPs on enhancing the PL properties has been underlined. • The 0.6 mol% of AgNO3 embedded glasses were beneficial for the optoelectronic devices. Efficacy of silver nanoparticles on photoluminescence properties on optimized Eu 2 O 3 doped borate glasses has been studied and discussed in detail. The presence of homogeneously distributed and spherically shaped Ag nanoparticles was confirmed by electron microscopic images. With increase of AgNO 3 concentration the photoluminescence intensity of Eu3+ transitions improved up to 0.6 mol% and subsequently quenched at 0.8 mol% of AgNO 3. The enhancement in photoluminescence properties observed as the AgNO 3 concentration raised to higher level was ascribed to local field effect and transmit of energy from Ag nanoparticles to the tri–positive europium ions. While the reduction in photoluminescence properties at higher doping level of AgNO 3 was attributed to reverse transmit of energy from tri–valent europium ions to Ag nanoparticles. Other mechanisms liable for the attenuation in photoluminescence properties are also highlighted. The energy transfer from Eu3+ ions to Ag0 nanoparticles was responsible for the reduction in radiative lifetime magnitudes. The studies suggest the glass sample containing 0.6 mol% of AgNO 3 (i.e. SNBEuAg0.6) beneficial for optoelectronic and photonic applications. [ABSTRACT FROM AUTHOR]

• Nonlinear optical and optical limiting properties of glasses were studied at 532 nm. • The radiation shielding characteristics were evaluated between 0.122 and 1.458 MeV. • The high Eu3+ containing glass is beneficial as the power optical limiter. • The shielding data suggest the high Eu3+ containing glass is the best attenuator. Effect of trivalent europium ions on optical nonlinear and limitng features of antimony sodium borate gasses was studied at 532 nm using Z-scan method with pumping under nanosecond laser pulses. The Z–scan profile of studied glasses in open aperture configuration showed two photon absorption which is because of reverse saturable absorption. As the Eu 2 O 3 concentration is elevated in the composition, the two–photon absorption coefficients were increased while the opposite trend has been noticed in optical limiting threshold values. This endorse, the high Eu3+ doped antimony sodium borate glasses are potential materials for fabricating the optical limiters to work in visible region for the safeguard of delicated instruments and also human eyes from high energy laser radaitions persuaded damages. Further, the linear attenuation coefficient (LAC) revealed the incorporation of Eu 2 O 3 enhances the LAC and thus an improvement on the shielding competence of the fabricated glasses occurs with the addition of Eu 2 O 3. The effective atomic number (Z eff) results showed that the maximum interactions between the photons and the atoms of the glasses occurs at 0.122 MeV and the glass samples have a good blocking ability to the photons. The half value layer (HVL) found that to reduces as the Eu3+ content elevated to higher level in the composition. The radiation shielding factors showed that SNBEu2 glass with the 2 mol % of Eu 2 O 3 is the superior shield out of the fabricated SNBEu x samples. [ABSTRACT FROM AUTHOR]

Influence of Heavy Metal Oxides (HMOs: PbO and Bi 2 O 3) on structural and photoluminescence (PL) properties Eu3+ activated lanthanum borate glasses has been analyzed and discussed in thoroughly here. When the PbO is loaded more and more in the glass system, the luminesce intensity and lifetime values of 5D 0 → 7F 2 transition of Eu3+ were improved for the excitation at 464 nm due to enhanced covalency of Eu–O bonds arose from the dual function of lead oxide in the structure of PbO varied glasses. The betterment in luminescence features are also attributed to the decrease of effective network phonon energy occurred because of the incorporation of lead oxide in the glass composition. On the other hand, the luminesce (emission intensity and lifetime values of 614 nm emission of Eu3+ under 464 nm excitation) results are completely upending as the Bi 2 O 3 content increased gradually in the glass matrix. This reduction in luminescence properties are ascribed to the decrease of covalency of Eu–O and thus crystal field in the vicinity of Eu3+ site. The reduction of covalent character of Eu–O is due to two facts, one being the newly generated NBOs owing to the generation of BiO 6 units with the incorporation of Bi 2 O 3 in the glass matrix and the second, the development of Bi–O–Bi and Bi–O–B linkages. The luminescence and spectroscopic attributes evidently reveal the lead varied borate glass hosts are more beneficial than Bi 2 O 3 varied borate glass hosts for optoelectronic applications. • Influence of PbO and Bi 2 O 3 on photoluminescence and structural properties of Eu3+ activated glasses has been investigated. • The structure–photoluminescence property correlation has been highlighted. • Results suggest the PbO containing glasses are more beneficial for solid–state and laser lighting applications. [ABSTRACT FROM AUTHOR]