Growth, Optical Properties, and Stimulated Emission of Nd-Doped Aluminates with the K2NiF4 Structure

1991 ◽  
Author(s):  
Horacio R. Verdùn ◽  
Leonard M. Thomas
Keyword(s):  
Optical Properties ◽  
Stimulated Emission ◽  
K2nif4 Structure

Molecular Beam Epitaxy of Znl-x Cdx Se/ZnSe Heterostructures And Their Optical Properties

1991 ◽  
Vol 228 ◽  
Author(s):  
H. Luo ◽  
N. Samarth ◽  
J. K. Furdyna ◽  
H. Jeon ◽  
J. Ding ◽  
...  
Keyword(s):  
Optical Properties ◽  
Molecular Beam Epitaxy ◽  
Quantum Wells ◽  
Room Temperature ◽  
Molecular Beam ◽  
Stimulated Emission ◽  
Optically Pumped ◽  
Absorption Coefficients ◽  
Excitonic Absorption ◽  
Lasing Mechanism

ABSTRACTSuperlattices and quantum wells of Znl-xCdxSe/ZnSe, and heterostructures based on ZnSe/CdSe digital alloys have been grown by molecular beam epitaxy (MBE). Their optical properties were studied with particular emphasis on excitonic absorption and photopumped stimulated emission. Excitonic absorption is easily observable up to 400 K, and is characterized by extremely large absorption coefficients (α = 2×105cm−1). Optically pumped lasing action is obtained at room temperature with a typical threshold intensity of 100 kW/cm2. The lasing mechanism in these II-VI quantum wells appears to be quite different from that in the better studied III-V materials: in our case, the onset of stimulated emission occurs before the saturation of the excitonic absorption, and the stimulated emission occurs at an energy lower than that of the excitonic absorption.

scholarly journals Stimulated Emission and Optical Properties of Solid Solutions of Cu(In,Ga)Se2 Direct Band Gap Semiconductors

2018 ◽  
Vol 85 (2) ◽  
pp. 267-273
Author(s):  
I. E. Svitsiankou ◽  
V. N. Pavlovskii ◽  
E. V. Lutsenko ◽  
G. P. Yablonskii ◽  
A. V. Mudryi ◽  
...  
Keyword(s):  
Optical Properties ◽  
Band Gap ◽  
Solid Solutions ◽  
Stimulated Emission ◽  
Direct Band Gap ◽  
Direct Band

scholarly journals Tailoring optical properties and stimulated emission in nanostructured polythiophene

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Alberto Portone ◽  
Lucia Ganzer ◽  
Federico Branchi ◽  
Rodrigo Ramos ◽  
Marília J. Caldas ◽  
...  
Keyword(s):  
Optical Properties ◽  
Stimulated Emission

scholarly journals Láser en odontología: fundamentos físicos y biológicos / Laser in Dentistry: Physical and Biological Foundations

2017 ◽  
Vol 35 (75) ◽  
Author(s):  
Jhon Fredy Briceño Castellanos ◽  
Diego Alejandro Gaviria Beitia ◽  
Yurani Angélica Carranza Rodríguez
Keyword(s):  
Optical Properties ◽  
Biological Effects ◽  
Wave Length ◽  
Stimulated Emission ◽  
Technology Usage ◽  
Review Of Literature ◽  
Laser Technology ◽  
Light Amplification ◽  
Show Evidence ◽  
Extinction Length

RESUMEN. Antecedentes: El láser es una tecnología cada vez más utilizada en Odontología. Para tomar decisiones acertadas con respecto a las características y uso del láser es importante conocer sus bases físicas y biológicas en cuanto a su interacción con los tejidos. Objetivo: Analizar los fundamentos biológicos y físicos del láser en odontología. Métodos: Se realizó una revisión narrativa con base en literatura publicada entre 1990 y 2016 e incluida en el Medline. La muestra consistió en 30 artículos. Para el análisis se empleó un enfoque hermenéutico. Resultados: Los fundamentos físicos analizados incluyen luz, amplificación, emisión estimulada y radiación. En cuanto a los efectos biológicos se analizan el fototérmico, fotoquímico y fotoacústico. Asimismo, se describen las propiedades ópticas de los tejidos orales:  absorción, penetración y longitud de extinción. Conclusiones: No todos los láseres actúan igual y una misma longitud de onda puede tener interacciones diferenciales en los tejidos. Existen varios estudios que evidencian la efectividad del láser en varias especialidades de la odontología y abren la posibilidad de varias líneas de investigación.ABSTRACT. Background: Laser technology usage is increasing in dentistry. In order to take adequate decisions about characteristics and use, it is important to know the physical and biological foundations of laser and its interaction with oral tissues. Objective: To analyze the physical and biological foundations of laser in dentistry. Methods: A narrative review of literature published between 1990 and 2016 and included in Medline was carried out. The sample consisted of 30 articles. Analysis of literature was performed through a hermeneutical approach Results: Physical foundations of laser analyzed include light, amplification, stimulated emission, and radiation. Biological effects studied are photothermal, photochemical, and photoacoustic. In addition, optical properties of oral tissues are described: absorption, penetration, and extinction length. Conclusion: Not all lasers act the same way and the same wave length can interact differently with tissues. Several studies show evidence of the effectiveness of laser in several dental specialties and open the possibility for several lines of research. 

Morphology and Optical Properties of ZnO Nanorods Grown by Catalyst-assisted Vapor Transport on Various Substrates

2006 ◽  
Vol 963 ◽  
Author(s):  
Vitaliy Avrutin ◽  
Umit Ozgur ◽  
Natalia Izyumskaya ◽  
Serguei Chevtchenko ◽  
Jacob Leach ◽  
...  
Keyword(s):  
Optical Properties ◽  
Substrate Surface ◽  
Zno Nanorods ◽  
Stimulated Emission ◽  
Conductive Atomic Force Microscopy ◽  
Vapor Phase Transport ◽  
Time Resolved ◽  
Force Microscopy ◽  
Atomic Force ◽  
Time Resolved Photoluminescence

ABSTRACTZnO nanorods were grown by catalyst-assisted vapor phase transport on Si(001), GaN(0001)/c-Al2O3, and bulk ZnO(0001) substrates. Morphology studies showed that ZnO nanorods grew mostly perpendicularly to the GaN substrate surface, whereas a more random directional distribution was found for nanorods on Si. Optical properties of fabricated nanorods were studied by steady-state photoluminescence and time-resolved photoluminescence. Stimulated emission was observed from ZnO nanorods on GaN substrates. Raman spectroscopy revealed biaxial strain in the nanorod samples grown on Si. Conductive atomic force microscopy was applied to study I-V spectra of individual nanorods.

Optical Properties of Mg-GaN, GaN/AlGaN SCH structures, and GaN on ZnO Substrates

1995 ◽  
Vol 395 ◽  
Author(s):  
H. Morkoç ◽  
W. Kim ◽  
Ö. Aktas ◽  
A. Salvador ◽  
A. Botchkarev ◽  
...  
Keyword(s):  
Optical Properties ◽  
Low Temperature ◽  
Room Temperature ◽  
Stimulated Emission ◽  
Lattice Match ◽  
Photoluminescence Emission ◽  
Stacking Order ◽  
Near Ultraviolet ◽  
Side Pumping ◽  
Low Temperature Photoluminescence

ABSTRACTGaN films and GaN/AlGaN heterostructures have been gro wn by MBE. GaN films doped with varying levels of Mg indicate effective mass acceptor at low doping concentrations, as determined from strong photoluminescence emission at about 380 nm. As the Mg concentration is increased the photoluminescence emission line red shifts considerably, indicating the formation of Mg-related or induced complexes whose lifetimes are relatively short. GaN/AlGaN separate confinement heterostructures grown on sapphire show strong near ultraviolet stimulated emission at room temperature in a side-pumping configuration. The pumping threshold for stimulated emission at room temperature was found to be ∼90 kW/cm2. Initial GaN films grown on ZnO substrates show the A exciton in low temperature photoluminescence. ZnO is being considered for nitride growth because of its stacking order and close lattice match.

scholarly journals Optical Properties and White Light Emission of Dy3+ Doped Alumino Borotellurite Glasses

2019 ◽  
Vol 35 (4) ◽  
Author(s):  
Phan Van Do
Keyword(s):  
Optical Properties ◽  
Light Emission ◽  
Transition Probability ◽  
Emission Cross Section ◽  
Optical Gain ◽  
Emission Feature ◽  
Stimulated Emission ◽  
Luminescence Spectra ◽  
Intensity Parameters ◽  
Chromaticity Coordinates

Dy3+ doped alumino borotellurite (ABT) glasses xB2O3+(80-x)TeO2+10Al2O3+10CaO+ 0.5Dy2O3 (where x = 35; 45 and 55) have been prepared by melting method. Their optical properties were studied through absorption, luminescence spectra and decay time measurements. Judd-Ofelt (JO) intensity parameters (Ωλ, λ = 2, 4 and 6) have been determined using absorption spectra and are been used to calculate the radiative parameters like transition probability, stimulated emission cross-section, branching ratios, gain band width and optical gain for the 4F9/2→6H13/2 transition in Dy3+ ions. The chromaticity coordinates is used to estimate the emission feature of prepared glasses.

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