A5011973991- Random lasers and scattering media
- Luminescence Properties of Advanced Materials
- Solid State Laser Technologies
- Quantum optics and atomic interactions
- Photorefractive and Nonlinear Optics
- Advanced Fiber Laser Technologies
- Glass properties and applications
- Photonic and Optical Devices
- Orbital Angular Momentum in Optics
- Neural Networks and Reservoir Computing
- Plant and animal studies
- Advanced Optical Imaging Technologies
- Optical and Acousto-Optic Technologies
- Photonic Crystals and Applications
- Optical properties and cooling technologies in crystalline materials
- Visual perception and processing mechanisms
- Terahertz technology and applications
- Phase-change materials and chalcogenides
- Laser-Matter Interactions and Applications
- Perovskite Materials and Applications
- Surface Roughness and Optical Measurements
- Diffusion and Search Dynamics
- Nonlinear Photonic Systems
- Spectroscopy and Laser Applications
- Theoretical and Computational Physics
Universidade Federal de Alagoas
2015-2024
Universidade Federal de Pernambuco
2015-2022
University at Buffalo, State University of New York
2015
Abstract Random lasers have been recently exploited as a photonic platform for studies of complex systems. This cross-disciplinary approach opened up new important avenues the understanding random-laser behavior, including Lévy-type distributions strong intensity fluctuations and phase transitions to spin-glass phase. In this work, we employ Nd:YBO random laser system unveil, from single set measurements, physical origin correspondence between Lévy fluctuation regime...
The photonic analog of the paramagnetic to spin-glass phase transition in disordered magnetic systems, signaled by phenomenon replica symmetry breaking, has been reported using random lasers as platform. We report here a demonstration breaking one-dimensional system consisting an erbium-doped fiber laser operating continuous-wave regime. is based on unique grating which plays role scattering, providing feedback mechanism. clear from phase, characterized Parisi overlap parameter, was verified...
We report on measurements of the statistical fluctuations output intensity in a continuous-wave-pumped erbium-doped one-dimensional random fiber laser (RFL), with specially designed Bragg grating scatterers. Transitions from Gaussian to Lévy-like and back regime, similar those observed three-dimensional lasers, are described as input excitation power increases below above RFL threshold. Our results consistent theoretical predictions for sequence regimes systems. also discuss experimental...
The spectroscopic characteristics of Er3+-doped lead phosphate glasses have been investigated, and Judd?Ofelt analysis was used to evaluate the effect increasing Er3+ content on glass matrices. intensity-dependent parameters, ?(4) ?(6), remained constant while ?(2) decreased. concentration quenching lifetime Er3+?:?4I13/2 ?4 I15/2 (1530?nm) transition is also evaluated as a result addition composition. observed relatively large reduction in reflects significant effects non-radiative...
By using specially designed nanoparticles scatterers which prevents photodegradation of the dye, we present clear demonstration replica symmetry break and a photonic paramagnetic to spin-glass phase transition in random laser operating incoherent feedback regime based on ethanol solution Rhodamine 6G amorphous TiO2 nanoparticles.
Abstract Random lasers (RLs) based on neodymium ions (Nd 3+ ) doped crystalline powders rely multiple light scattering to sustain laser oscillation. Although Stokes and anti-Stokes Nd RLs have been demonstrated, the optical gain obtained up now was possibly not large enough produce self-frequency conversion. Here we demonstrate upconversion from YAl 3 (BO 4 monocrystals excited at 806 nm, in resonance with transition I 9/2 → F 5/2 . Besides observation of RL emission 1062 self-converted...
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Abstract Ultraviolet and blue light were obtained by nonlinear frequency conversion in a random laser (RL) based on Nd 0.10 Y 0.90 Al 3 (BO ) 4 nanocrystalline powder. RL operation at 1062 nm, due to the F 3/2 → I 11/2 transition of neodymium ions (Nd 3+ ), was achieved exciting with tunable beam from 680 920 nm covering ground state absorption transitions 9/2 , ( 7/2 S 5/2 2 H states. Light 340 460 via second-harmonic generation excitation while light, 417 486 generated self-sum-frequency...
We report efficient nonresonant ground-state excitation at 1064 nm of trivalent neodymium (Nd3+) ions in stoichiometric aluminum borate NdAl3(BO3)4 nanoparticles, which are crystalline and, besides the large content Nd3+ ions, present excellent photoluminescence properties. Upconversion (UC) emission was observed, and energy pathways were identified starting from multi-phonon assisted absorption (4I9/2 → 4F3/2) excited-state (4I11/2 with population 4I11/2 level by thermal coupling ground...
The interplay between gain and scattering of light propagating in disordered media allows operation random lasers (RLs)-lasers without conventional optical cavities. In the present paper, we review our recent contributions this area, which include demonstration self-second-harmonic self-sum-frequency generation, characterization Lévy's statistics output intensity fluctuations, replica symmetry breaking (analogue to spin-glass phase transition) by RLs based on nanocrystals containing...
Disordered light has recently been introduced as a novel and efficient approach for pumping random lasers (RLs), resulting in reduced lasing threshold enhanced emission intensity. Here, we investigate the photon propagation, coming from both homogeneous disordered patterns, within scattering media to understand influence of disorder spatial intensity wavevector distributions pump on RL optimization. For this purpose, an adapted coherent backscattering (CBS) technique was employed measure...
Random laser (RL) emission in Nd3+ doped potassium gadolinium tungstate—KGd(WO4)2:Nd3+—crystal powder is demonstrated. The was excited at 813 nm resonance with the transition 4I9/2→4F5/2. RL 1067 due to 4F3/2→4I11/2 observed and characterized. An intensity threshold dependent on spot area bandwidth narrowing from ≈2.20 ≈0.40 were measured. For a beam of 0.4 mm2, 6.5 mJ/mm2 (90 MW/cm2) determined. excitation smaller than threshold, only spontaneous level 4F3/2 decay time tens microsecond...
We demonstrate the replica symmetry breaking (RSB) phenomenon in spontaneous mode-locking regime of a multimode Q-switched Nd:YAG laser. The underlying mechanism is quite distinct from that RSB recently observed random lasers. Here, there no medium and phase not glassy with incoherently oscillating modes as Instead, each pulse specific subset longitudinal are activated nondeterministic way, whose coherent oscillation dominates frustrates others. emergence coincides onset ultrashort...
Taking into account relaxing Kerr nonlinearity and walk-off effects, the conditions gain spectra of cross-phase modulation-induced modulational instability (XPM-MI) two incoherently copropagating optical waves different frequencies same polarization are investigated. We devote particular attention to mixed case in which one pulse propagates under normal group-velocity dispersion (GVD) regime, while second is an anomalous GVD regime. unveil that limit instantaneuous nonlinear response,...
Morphological, structural and optical properties of Nd<sup>3+</sup>/Yb<sup>3+</sup>codoped Al<sub>4</sub>B<sub>2</sub>O<sub>9</sub>nanopowders prepared by the polymeric precursor method were investigated.