Time-resolved photoluminescence in a-SiNx:H〈Nd〉 planar waveguides: evidence for stimulated emission

2005 ◽  
Vol 27 (5) ◽  
pp. 773-775 ◽  
Author(s):  
Daniel Biggemann ◽  
Leandro R. Tessler
Keyword(s):  
Stimulated Emission ◽  
Planar Waveguides ◽  
Time Resolved ◽  
Time Resolved Photoluminescence

scholarly journals Time-resolved photoluminescence study of the stimulated emission in ZnO nanoneedles

2005 ◽  
Vol 87 (9) ◽  
pp. 093108 ◽  
Author(s):  
W. M. Kwok ◽  
A. B. Djurišić ◽  
Y. H. Leung ◽  
W. K. Chan ◽  
D. L. Phillips
Keyword(s):  
Stimulated Emission ◽  
Time Resolved ◽  
Photoluminescence Study ◽  
Time Resolved Photoluminescence

Time-resolved photoluminescence studies of stimulated emission and exciton dynamics in ZnSe/ZnS0.18Se0.82 superlattices

1994 ◽  
Vol 37 (4-6) ◽  
pp. 1133-1136
Author(s):  
C.J. Stevens ◽  
R.A. Taylor ◽  
J.F. Ryan ◽  
M. Dabbicco ◽  
M. Ferrara ◽  
...  
Keyword(s):  
Stimulated Emission ◽  
Time Resolved ◽  
Exciton Dynamics ◽  
Photoluminescence Studies ◽  
Time Resolved Photoluminescence

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.

scholarly journals Gain lifetime characterization through time-resolved stimulated emission in a whispering-gallery mode microresonator

Nanophotonics ◽  
2018 ◽  
Vol 8 (1) ◽  
pp. 127-134 ◽  
Author(s):  
Xiao-Fei Liu ◽  
Fuchuan Lei ◽  
Tie-Jun Wang ◽  
Gui-Lu Long ◽  
Chuan Wang
Keyword(s):  
Precise Measurement ◽  
Collection Efficiency ◽  
Photonic Devices ◽  
Stimulated Emission ◽  
Probe Signal ◽  
Time Resolved ◽  
High Q ◽  
Whispering Gallery ◽  
Erbium Doped ◽  
Time Resolved Photoluminescence

AbstractThe precise measurement of gain lifetime at a specific wavelength holds significant importance for understanding the properties of photonic devices and further improving their performances. Here, we show that the evolution of gains can be well characterized by measuring linewidth changes of an optical mode in a microresonator; this method cannot be achieved using time-resolved photoluminescence (PL) spectroscopy. We use an erbium-doped high-Q whispering-gallery microresonator to show the feasibility of this method. With the increase of time after the pump laser is turned off, the transmission spectrum of a probe signal exhibits transitions from a Lorentz peak to a dip; this indicates a decay of optical gains, and the corresponding lifetime is estimated to be 5.1 ms. Moreover, taper fiber coupling is used to increase the pump and collection efficiency. This method can be extended to other materials and nanostructures.

scholarly journals Stimulated emission and time-resolved photoluminescence in rf-sputtered ZnO thin films

2004 ◽  
Vol 84 (17) ◽  
pp. 3223-3225 ◽  
Author(s):  
Ü. Özgür ◽  
A. Teke ◽  
C. Liu ◽  
S.-J. Cho ◽  
H. Morkoç ◽  
...  
Keyword(s):  
Thin Films ◽  
Stimulated Emission ◽  
Zno Thin Films ◽  
Time Resolved ◽  
Time Resolved Photoluminescence

Spontaneous and Stimulated Recombination in the Nitrides

1996 ◽  
Vol 449 ◽  
Author(s):  
A. Hangleiter ◽  
F. Scholz ◽  
V. Härle ◽  
J. S. Im ◽  
G. Frankowsky
Keyword(s):  
Quantum Wells ◽  
Room Temperature ◽  
Optical Gain ◽  
Stimulated Emission ◽  
Time Resolved ◽  
Double Heterostructures ◽  
Bulk Gan ◽  
Photoluminescence Studies ◽  
Excitonic Effects ◽  
Time Resolved Photoluminescence

ABSTRACTBoth spontaneous and stimulated emission processes are essential ingredients for constructing a laser from the nitrides. Based on our picosecond time-resolved photoluminescence studies we show that spontaneous radiative recombination is strongly influenced by excitonic effects, both in bulk GaN and in quantum wells. Particularly in quantum wells, localization of excitons plays an important role. We have studied the optical gain spectra in GaInN/GaN and GaN/AlGaN double heterostructures and quantum wells, grown by LP-MOVPE, using the stripe excitation method. Both room temperature and low temperature measurements were performed. Based on our results, we discuss the physical mechanism of optical gain in the nitrides as well as consequences for laser operation. We show that localization or, equivalently, the formation of quantum dot like structures, governs the optical gain mechanism in the nitrides.

Exciton dynamics in thick GaN MOVPE epilayers deposited on sapphire.

1997 ◽  
Vol 2 ◽  
Author(s):  
J. Allègre ◽  
P. Lefebvre ◽  
J. Camassel ◽  
B. Beaumont ◽  
Pierre Gibart
Keyword(s):  
Layer Thickness ◽  
Buffer Layers ◽  
Rate Equations ◽  
Time Resolved ◽  
Versus Layer ◽  
Level Model ◽  
Shallow Impurities ◽  
Aln Buffer ◽  
Time Resolved Photoluminescence

Time-resolved photoluminescence spectra have been recorded on three GaN epitaxial layers of thickness 2.5 μm, 7 μm and 16 μm, at various temperatures ranging from 8K to 300K. The layers were deposited by MOVPE on (0001) sapphire substrates with standard AlN buffer layers. To achieve good homogeneities, the growth was in-situ monitored by laser reflectometry. All GaN layers showed sharp excitonic peaks in cw PL and three excitonic contributions were seen by reflectivity. The recombination dynamics of excitons depends strongly upon the layer thickness. For the thinnest layer, exponential decays with τ ~ 35 ps have been measured for both XA and XB free excitons. For the thickest layer, the decay becomes biexponential with τ1 ~ 80 ps and τ2 ~ 250 ps. These values are preserved up to room temperature. By solving coupled rate equations in a four-level model, this evolution is interpreted in terms of the reduction of density of both shallow impurities and deep traps, versus layer thickness, roughly following a L−1 law.

ZnCdO/ZnMgO and ZnO/AlGaN Heterostructures for UV and Visible Light Emitters

2005 ◽  
Vol 892 ◽  
Author(s):  
Andrei Osinsky ◽  
Jianwei Dong ◽  
J. Q. Xie ◽  
B. Hertog ◽  
A. M. Dabiran ◽  
...  
Keyword(s):  
Molecular Beam ◽  
Compositional Analysis ◽  
Optical Emission ◽  
Rf Plasma ◽  
Light Emitters ◽  
Time Resolved ◽  
Light Emitting ◽  
Spatially Resolved ◽  
Time Resolved Photoluminescence ◽  
Made In

AbstractThis paper reviews of some of the progress made in the development of ZnO-based light emitting diodes (LEDs). n-ZnO/p-AlGaN-based heterostructures have been successfully for the fabrication of UV emitting LEDs that have operated at temperatures up to 650K, suggesting an excitonic origin for the optical transitions. RF-plasma-assisted molecular beam epitaxy has been used to grow epitaxial CdxZn1-xO films on GaN/sapphire structure. These films have a single-crystal wurtzite structure as demonstrated by structural and compositional analysis. High quality CdxZn1-xO films were grown with up to x=0.78 mole fraction as determined by RBS and SIMS techniques. Optical emission ranging from purple (Cd0.05Zn0.95O) to yellow (Cd0.29Zn0.71O) was observed. Compositional fluctuations in a Cd0.16Zn0.84O films were not detected by spatially resolved CL measurements, although intensity fluctuation with features of ∼0.5 μm diameter were seen on the intensity maps. Time resolved photoluminescence shows multi-exponential decay with 21 psec. and 49±3 psec. lifetimes, suggesting that composition micro-fluctuations may be present in Cd0.16Zn0.84O film.

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