Generation Of Red Light Research Articles

Study of photoluminescence behaviors and Judd-Ofelt analysis of Eu3+ doped double perovskite Ba2GdSbO6 phosphor for highly pure and strong red-light generation

An array of Eu3+ doped Ba2GdSbO6 luminescent materials have been synthesized by the conventional solid-state (high temperature) reaction route. Surface morphology has been studied via Field Emission Scanning Electron Microscopy. The structural and optical behaviors have been studied using X-Ray Diffraction (XRD), FTIR, Raman spectroscopy, Diffuse reflectance spectroscopy, Photoluminescence excitation (PLE), and Photoluminescence emission (PL) spectra. FTIR and Raman's spectra provided the chemical functional group and different vibrational levels within the samples. The calculated optical band gap was 4.40 eV and 4.47eV for pure and optimized samples respectively. Photoluminescence emission curves have been recorded for 245 nm of excitation wavelength and the highest emission peak was focused at 595 nm corresponding to 5D0 → 7F1. Similarly, the Photoluminescence excitation curves were monitored at the emission wavelength of 595 nm and a broad charge transfer band (CTB) was observed from 230 to 285 nm. The emission spectra show the concentration quenching effect beyond the 2 mol% Eu3+ concentration. The corresponding transitions of Eu3+ were further utilized to obtain the Judd-Ofelt (J-O) transition intensity parameters Ωλ (λ = 2, 4) for each sample. Additionally, by studying decay kinetics, the average lifetime of the red emission of the samples has been evaluated, which was 4.622 ms. The photometric study also reveals the CIE coordinates, color purity and CCT values of the proposed phosphor material. Thus, the results obtained from these characterizations, suggest that the prepared sample may behave as a potential candidate in the case of UV-excited red light-emitting phosphor material for light-emitting diodes and field emission devices.

Generation of red light with intense photoluminescence assisted by Forster resonance energy transfer from Znq2 and DCM thin films

In this work, a novel experimental investigation of photoluminescence properties of Znq2 thin films co-doped with different concentrations of DCM were performed. The thin films were successfully deposited on glass substrates with different compositions, under high vacuum, by using the vacuum evaporation technique. For all compositions, the photoluminescence was measured at room temperature and also at low temperature in a wide range from 77 to 300 K with a step of 25 K in a high vacuum. The lifetime of the sample studied in real time was also measured using the decay time technique. The results obtained confirm that the doping influences the intensity of the DCM photoluminescence and also shows a complete energy transfer occurred from Znq2 to DCM which may have shifted the photoluminescence peak from Znq2 to the orange wavelength region which is related to DCM. The lifetime of the sample studied in real time was about 4.47 ns for Znq2 and while all the other samples showed two decay time components. As a result, the doping influences the optical properties of Znq2 and makes it a potential candidate for optoelectronic applications.Graphical abstract

Structural and photoluminescence properties of europium oxide doped fluoroborate optical glasses

A sequence of zinc-magnesium-lithium-fluoroborate (ZMLB) optical glasses doped with different Eu3+ concentrations were synthesized through melt quenching technique. The non-crystalline characteristic of the synthesized glasses was proved by X-ray diffraction studies and the FT-IR transmittance spectra have been used to study the various vibrational bands in glass systems. The photoluminescence characteristics were studied under an excitation with 393 nm and it exhibits four emission peaks around at 590, 615, 654 and 700 nm assigned to 5D0→7F1, 5D0→7F2, 5D0→7F3 and 5D0→7F4 electronic transitions of Eu3+ ion, respectively. Color chromaticity values were estimated from luminescence spectra for all the synthesized samples and these parameters indicate the emission in red color region and cold light emission. All these results suggest that the Eu3+ ions doped ZMLB glasses are a potential candidate for red light generation at 615 nm to explore the new material for solid state light emitting diode applications.

Investigation of europium-doped aluminium phosphate glass for red light generation

Europium doped phosphate glasses (KPEu) with various concentrations of Eu 2 O 3 were prepared by a melt-quenching method for red light application. The prepared samples were characterized using physical, absorption, photoluminescence, X-ray induced luminescence (XEL) and J-O analysis techniques. Density, molar volume and refractive index of the investigated glasses increased with increasing concentration of Eu 2 O 3 . Eight absorption peaks were observed, with six peaks in the visible region (350–550) nm and two in the infrared region (2000–2200). Four emission peaks were observed in the visible region when the glass was excited at 394 nm. Judd-Ofelt (JO) intensity parameters (Ω λ λ = 2, 4, 6) were determined using the JO-theory for the prepared glass samples. The radiative properties of the glasses were determined using JO-parameter, refractive index and emission spectra. The trend of JO parameters for the present KPEu 6 glass sample were Ω 2 > Ω 4 > Ω 6 . These glasses also showed higher branching ratios and stimulated emission cross section ( σ e ) values, making these suitable for red laser applications. XEL showed the same peaks and trend as emission spectra but its peaks were shifted and had high intensity. The luminescence colours of these glass samples entirely fall in the reddish orange region (x = 0.653–0.654, y = 0.346–0.347) as confirmed by CIE 1931 diagram. The CCT values of the prepared glass samples were in the range of 2394–2431 K.

Efficient 671 nm red light generation in annealed proton-exchanged periodically poled LiNbO3 waveguides

We report efficient generation of 671 nm red light based on quasi-phase-matched second harmonic generation of 1342 nm in LiNbO3 waveguides. The design method and fabrication process of the high-quality annealed proton-exchanged periodically poled channel waveguides were presented. A continuous-wave 1.71 mW red light was obtained with a single-pass conversion efficiency of 47%·W-1·cm-2, which is 88% that of the theoretical value. While for 1 mW quasi-continuous-laser input, the corresponding peak power being 2 W, the conversion efficiency reached up to 60%. Our results indicate that the annealed proton-exchanged periodically poled LiNbO3 waveguide is promising for high-efficiency and low power consumption nonlinear generation of visible light.

Local Field Effect in antimony-germanate glasses co-doped with Rare-Earth ions and silver nanoparticles

The article presents the possible mechanisms of interaction between emission of Eu3+ ions and surface plasmon resonance (SPR) from Ag0 nanoparticles. The antimony-germanate glasses were synthetized by standard melt-quenching method. The influence of high-phonon glass forming compounds on excitation and luminescence spectra was analysed. Also, we showed that Sb2O3 is a mild reducing agent of noble metal ions. This mild reduction property enables thermochemical reduction of Ag+ to Ag0 in a single-step during the melting process. The energy transfer mechanisms between Eu3+ ions and Ag0 nanoparticles were also discussed in terms of local field effect of Ag0 nanoparticles. Full Text: PDF ReferencesS. Chatterjee, S. K. Saha, and D. Chakravorty, "Glass-Based Nanocomposites" in Glass Nanocomposites, B. Karmakar, K. Rademann and A. L. Stepanov, (Eds.: William Andrew Publishing, Boston, 2016) DirectLink D. Dorosz, et al., "Structural and optical study on antimony-silicate glasses doped with thulium ions", Spectrochim. Acta A 134, 608 (2015). CrossRef J. Zmojda, et al., "Effect of GeO2 content on structural and spectroscopic properties of antimony glasses doped with Sm3+ ions", J Mol. Struct. 1126, 207 (2016) CrossRef J. Zmojda, D. Dorosz, M. Kochanowicz, J. Dorosz, "Spectroscopic properties of Yb3+/Er3+ - doped antimony-phosphate glasses for fiber amplifiers", Phot. Lett. Poland 2, 76 (2010) CrossRef M. Eichelbaum and K. Rademann, "Plasmonic Enhancement or Energy Transfer? On the Luminescence of Gold-, Silver-, and Lanthanide-Doped Silicate Glasses and Its Potential for Light-Emitting Devices", Adv. Funct. Mater. 19, 2045 (2009) CrossRef Binnemans, K. Coord. "Interpretation of europium(III) spectra", Chem. Rev. 295, 1 (2015) CrossRef S. Selvi, K. Marimuthu, N. S. Murthy, G. Muralidharan, "Red light generation through the lead boro?telluro?phosphate glasses activated by Eu3+ ions", J Mol. Struct. 1119, 276 (2016) CrossRef J. Zmojda, et al., "Optical Characterization of Nano- and Microcrystals of EuPO4 Created by One-Step Synthesis of Antimony-Germanate-Silicate Glass Modified by P2O5", Materials 10, 1059 (2017) CrossRef N. Shasmal, B. Karmakar, "Enhancement and tuning of photoluminescence properties in Pr3+/Au co-doped antimony oxide glass nanocomposites by thermal treatment", J Alloy. Compd. 688, 313 (2016) CrossRef

Spectroscopic investigation on europium doped heavy metal borate glasses for red luminescent application

The present study explores a new borate family glasses based on 10ZnO–5Na2O–10Bi2O3–(75 − x) B2O3–xEu2O3 (x = 0, 0.1, 0.5, 1, 1.5, 2, 3 mol%) composition, synthesized by rapid melt quench technique. Prepared glasses were subjected to the density and refractive index measurements and their values were used to calculate other physical properties of the glass matrix as a function of Eu3+ concentration. XRD confirmed amorphous nature of the glasses. FTIR spectra in the absorption mode were recorded in the 400–4000 cm−1 region to identify different functional groups in the glass matrix. Deconvoluted FTIR spectra showed increase in BO4 units with rise in europium content which confirmed the ‘network strengthener’ role of europium ions by creating bridging oxygens (BOs). Optical properties were investigated for their luminescence behavior through various spectroscopic techniques such as UV–Vis–NIR absorption, excitation, emission, decay profiles, and color measurements at room temperature. Lasing properties of the glasses like total radiative life time, branching ratio, emission cross section, and optical gain were obtained from the calculated Judd–Ofelt (Ω2,Ω4) intensity parameters. From the measured values of emission, cross sections, branching ratios, life times, strong photoluminescence features, and CIE chromaticity coordinates, 0.5 mol% of Eu3+ ions doped ZnNaBiB glasses showed optimum performance and are potential candidate for red light generation at 613 nm.

Red light generation through the lead boro−telluro−phosphate glasses activated by Eu3+ ions

Lead boro−telluro−phosphate glasses containing 0.05 to 2.0 wt% of Eu3+ ions were prepared through melt quenching technique. Structural characteristics of title glasses were identified through XRD, FTIR and Raman studies. The optical properties of the prepared glasses were studied using UV–Vis–NIR absorption and photoluminescence spectra. From the resultant spectra, we have obtained the bonding parameters (δ), nephelauxetic ratio (β), direct and indirect band gaps and Urbach energy (ΔE) values. A deep red luminescence due to 5D0 → 7F2 transition of Eu3+ ions could be observed for the title glasses. The local site symmetry around the Eu3+ ions and the degree of Eu3+−O2− covalence were assessed from the luminescence intensity ratio of 5D0 → 7F2/5D0 → 7F1 transitions. Judd−Ofelt intensity parameters, calculated from the luminescence spectra, were used to estimate the radiative parameters like transition probability (A), branching ratio (βexp, βcal) and stimulated emission cross-section (σPE) concerning the 5D0 → 7FJ (J = 0, 1, 2, 3 and 4) transitions. The important laser parameters, gain bandwidth and optical gain are also estimated. The decay curves associated with the transition from 5D0 state was found to be single-exponential at all Eu3+ ion concentrations. CIE colour coordinates and colour purity of the prepared glasses were estimated from the CIE chromaticity diagram.

Generation of Red Light Femtosecond Pulses from an Intra-Cavity Frequency-Doubled Cr4+: Forsterite Laser

We demonstrate the generation of red light femtosecond laser pulses from an intra-cavity frequency-doubled Cr4+ :forsterite laser. An average output power of 75 mW is obtained at the central wavelength of 647 nm with a pulse width of 55 fs by inserting a 500-μm-thick BBO crystal in the laser cavity. The bandwidth of the spectrum of second harmonic pulses is 9 nm, corresponding to a time-bandwidth product of 0.355.

12-W red light generation by frequency-doubling Q-switched Nd:YAG laser

By using a 15 mm-long type I phase-matching LBO crystal, a maximum quasi-continuous wave red laser output power of 12 W has been obtained by intra-cavity second-harmonic generation (SHG) in a compact acousto-optically Q-switched diode-side-pumped Nd:YAG laser. The corresponding optical-optical conversion efficiency is 6.6%. The power instability at the maximum output power is observed to be less than 4.62% during half an hour. The beam quality factor M2 is measured to be 9.9 ± 1.0 by the knife-edge method. The spectrum of the red radiation is also measured and discussed.

Simultaneously phase-matched blue and red light generation using BIBO

BiB3O6 has been found to be simultaneously phase matchable for sum-frequency generation at 0.4627 and 0.6260 microm by mixing the outputs of a 0.5321 microm pumped parametric oscillator with the fundamental source at 1.0642 microm. The simultaneous blue and red light generation is achieved under the temperature-insensitive phase-matching condition, and the relative strength of blue and red light can be controlled by changing the effective nonlinear constants through the azimuth angle. In addition, wide wavelength tuning of the simultaneous phase matching is obtained by the use of a noncollinear geometry, enabling a compact red-green-blue laser system based on the powerful solid-state laser.

High-power red-green-blue laser light source based on intermittent oscillating dual-wavelength Nd:YAG laser with a cascaded LiTaO_3 superlattice

We demonstrate a high-power red-green-blue laser source based on the quasi-phase-matching and intermittent oscillating dual-wavelength laser technique. A cascaded LiTaO3 superlattice was used to achieve the generation of red light at 660 nm, green light at 532 nm, and blue light at 440 nm to obtain the output of red-green-blue laser light from a diode-side-pumped Q-switched intermittent oscillating dual-wavelength Nd:YAG laser. The average output power of red-green-blue of 1.01 W was achieved under the total fundamental power of 5.1 W, which corresponds to the conversion efficiency of 20%.

Generation of red light at 660 nm by frequency doubling a Nd:YAG laser with periodically-poled stoichiometric LiTaO3

High power red light was generated from a periodically-poled stoichiometric LiTaO3 (PPSLT) by single-pass frequency doubling of a diode-side-pumped, Q-switched Nd:YAG laser at 1319 nm. An average power of 2.4 W of the 660 nm red light was obtained at the fundamental power of ∼5.4 W with the conversion efficiency up to 44.4% and with low fluctuation down to 2%. The high efficiency and stability at the red output indicate that it is a practical method to construct a reliable compact red laser.

High-Power Red Light Generation by Intra-CavityFrequency-Doubling of a Side-Pumped Nd:YAG Laser in a LiB3O5Crystal

We report the generation of high-power red light radiation of 11.2 W ina LiB3O5(LBO) crystal with intra-cavity frequencydoubling of two compact and simple side-pumped Nd:YAG laser modulesunder a repetition rate of 3.5 kHz. The pulse width of output is about180±20 ns. The beam quality of the M2 value is 15±3 inboth the directions. This excellent laser performance demonstrates thatthe Nd:YAG laser with LBO intracavity frequency doubling is anpromising method for generating red light with high brightness.

Efficient generation of red light by frequency doubling in a periodically-poled nearly-stoichiometric LiTaO3 crystal

An efficient generation of red light in a periodically-poled nearly-stoichiometric LiTaO3 (PPSLT) by extracavity single-pass frequency doubling of a diode-pumped, Q-switched Nd:YVO4 laser at 1342nm was realized. An average power of 1.4W of the 671nm red light is obtained at the fundamental power of ∼2.8W with the conversion efficiency of 50%. The high conversion efficiency and steady output of red light indicate that the thick PPSLT is a competitive candidate for frequency conversion in order to construct a compact all-solid-state red laser.

High-brightness 2.4-W continuous-wave Nd:GdVO4 laser at 670 nm.

We report on a diode-pumped 1.3-microm Nd:GdVO4 cw laser, intracavity doubled for highly efficient generation of red light. We obtained as much as 2.4 W of power at 670 nm (corresponding to 26% optical-to-optical efficiency) in a nearly TEM00 mode and with small amplitude noise. To the best of our knowledge, these results represent the highest performance at this wavelength for cw solid-state lasers.

Efficient Generation of Red and Blue Light in a Dual-StructurePeriodically Poled LiTaO3 Crystal

We demonstrate the efficient generation of red light at 671 nm and bluelight at 447 nm from a diode-pumped Q-switched 1342 nm Nd:YVO4 lasertogether with a periodically poled LiTaO3 (PPLT) crystal. Thesample used in this experiment is a dual-structure PPLT crystal withthe period of 14.9 μm for the second harmonic generation and that of4.9 μm for the third harmonic generation. The red and blue light, withthe respective average power of 752 mW and 153 mW were obtained in asingle path under an average fundamental power of 1.74 W, correspondingto the conversion efficiencies of 43.2% and 8.8%, respectively. Theseresults indicate that the dual-structure PPLT can be used to constructa compact and efficient all-solid-state red-and-blue dual-wavelengthlaser.

Generation of 840 mW of red light by frequency doubling a diode-pumped 1342 nm Nd:YVO4 laser with periodically-poled LiTaO3

We report an efficient generation of red light in a periodically-poled LiTaO3 (PPLT) crystal by extracavity single-pass frequency doubling of a diode-pumped, Q-switched Nd:YVO4 laser at 1342 nm. The sample used in the experiment is 20 mm in length and 14.77 μm in period. An average power of 840 mW of the 671 nm red light is obtained with a 808 nm pump of 12.3 W, the overall optical-to-optical efficiency being 6.8%. The measured effective nonlinear coefficient of the sample is ∼3.8 pm/V. The high conversion efficiency and output power demonstrate that the periodically-poled crystal serving as a frequency conversion device may be used in practice to construct an all-solid-state red laser based on an extracavity single-pass quasi-continuous scheme.

A scheme to realize three-fundamental-colors laser based on quasi-phase matching

A simultaneous generation of red light at 631 nm and blue light at 460 nm was realized, in single-pass quasi-phase-matched scheme, from two periodical optical superlattices in the same LiTaO 3 crystal in series. Using a 532 nm laser as pump, the red light was generated at 631 nm as the signal of optical parametric process in the first superlattice, and the blue light at 460 nm was the sum-frequency mixing the idler and the pump in the second superlattice. Along with the remnant pump at 532 nm, red light, green light and blue light can be obtained from the superlattice system simultaneously. This may be an emulous scheme to realize a compact three-fundamental-colors laser in future.

Red light generation by sum frequency mixing ofEr/Yb fibre amplifier output in QPM LiNbO 3

Red light was generated by the sum frequency mixing of 1.55 µm emission of an Er/Yb doped fibre amplifier with the unabsorbed 1.064 µm pump light in a 2.3 cm long periodically poled LiNbO3 crystal. A maximum power of 0.45 W was generated at 630 nm.