Threshold gain properties of lasing modes in ID disordered media optically pumped by femtosecond-lasing pulse

2011 ◽  
Vol 4 (4) ◽  
pp. 387-392
Author(s):  
Yong Liu ◽  
Jinsong Liu
Keyword(s):  
Disordered Media ◽  
Optically Pumped ◽  
Lasing Pulse ◽  
Lasing Modes ◽  
Threshold Gain

Study of Near-Threshold Gain Mechanisms in MOCVD-Grown GaN Epilayers and InGaN/GaN Heterostructures

1999 ◽  
Vol 572 ◽  
Author(s):  
S. Bidnyk ◽  
T. J. Schmidt ◽  
B. D. Little ◽  
J. J. Song
Keyword(s):  
Quantum Wells ◽  
Stimulated Emission ◽  
Multiple Quantum Wells ◽  
Multiple Quantum ◽  
Optically Pumped ◽  
Electron Hole ◽  
Electron Hole Plasma ◽  
Narrow Emission ◽  
Threshold Gain ◽  
Near Threshold

ABSTRACTWe report the results of an experimental study on near-threshold gain mechanisms in optically pumped GaN epilayers and InGaN/GaN heterostructures at temperatures as high as 700 K. We show that the dominant near-threshold gain mechanism in GaN epilayers is inelastic excitonexciton scattering for temperatures below ∼ 150 K, characterized by band-filling phenomena and a relatively low stimulated emission (SE) threshold. An analysis of both the temperature dependence of the SE threshold and the relative shift between stimulated and band-edge related emission indicates electron-hole plasma is the dominant gain mechanism for temperatures exceeding 150 K. The dominant mechanism for SE in InGaN epilayers and InGaN/GaN multiple quantum wells was found to be the recombination of carriers localized at potential fluctuations resulting from nonuniform indium incorporation. The SE spectra from InGaN epilayers and multiple quantum wells were comprised of extremely narrow emission lines and no spectral broadening of the lines was observed as the temperature was raised from 10 K to over 550 K. Based on the presented results, we suggest a method for significantly reducing the carrier densities needed to achieve population inversion in GaN, allowing for the development of GaNactive-medium laser diodes.

Microstructure-Based Lasing in GaN/AlGaN Separate Confinement Heterostructures

1999 ◽  
Vol 595 ◽  
Author(s):  
S. Bidnyk ◽  
J. B. Lam ◽  
B. D. Little ◽  
G. H. Gainer ◽  
Y. H. Kwon ◽  
...  
Keyword(s):  
Strain Relaxation ◽  
Laser Diodes ◽  
Ultra Violet ◽  
Temperature Stability ◽  
Far Field ◽  
Optically Pumped ◽  
Lasing Wavelength ◽  
Field Patterns ◽  
Low Threshold ◽  
Lasing Modes

AbstractWe report on an experimental study of microstructure-based lasing in an optically pumped GaN/AlGaN separate confinement heterostructure (SCH). We achieved low-threshold ultra-violet lasing in optically pumped GaN/AlGaN separate confinement heterostructures over a wide temperature range. The spacing, directionality, and far-field patterns of the lasing modes are shown to be the result of microcavities that were naturally formed in the structures due to strain relaxation. The temperature sensitivity of the lasing wavelength was found to be twice as low as that of bulk-like GaN films. Based on these results, we discuss possibilities for the development of ultra-violet laser diodes with increased temperature stability of the emission wavelength.

scholarly journals Microstructure-based lasing in GaN/AlGaN separate confinement heterostructures

2000 ◽  
Vol 5 (S1) ◽  
pp. 661-667
Author(s):  
S. Bidnyk ◽  
J. B. Lam ◽  
B. D. Little ◽  
G. H. Gainer ◽  
Y. H. Kwon ◽  
...  
Keyword(s):  
Strain Relaxation ◽  
Laser Diodes ◽  
Ultra Violet ◽  
Temperature Stability ◽  
Far Field ◽  
Optically Pumped ◽  
Lasing Wavelength ◽  
Field Patterns ◽  
Low Threshold ◽  
Lasing Modes

We report on an experimental study of microstructure-based lasing in an optically pumped GaN/AlGaN separate confinement heterostructure (SCH). We achieved low-threshold ultra-violet lasing in optically pumped GaN/AlGaN separate confinement heterostructures over a wide temperature range. The spacing, directionality, and far-field patterns of the lasing modes are shown to be the result of microcavities that were naturally formed in the structures due to strain relaxation. The temperature sensitivity of the lasing wavelength was found to be twice as low as that of bulk-like GaN films. Based on these results, we discuss possibilities for the development of ultra-violet laser diodes with increased temperature stability of the emission wavelength.

Controling the type of lasing modes in disordered media based on GaAs-AlGaAs nanowires

2021 ◽  
Author(s):  
Mohammad Rashidi ◽  
Tuomas Haggren ◽  
Zhicheng Su ◽  
Chennupati Jagadish ◽  
Sudha Mokkapati ◽  
...  
Keyword(s):  
Disordered Media ◽  
Lasing Modes

RF energy coupling to high-pressure optically pumped nonequilibrium plasmas

2001 ◽  
Author(s):  
Peter Palm ◽  
Elke Plonjes ◽  
Wonchul Lee ◽  
Kraig Frederickson ◽  
Walter Lempert ◽  
...  
Keyword(s):  
High Pressure ◽  
Energy Coupling ◽  
Optically Pumped ◽  
Nonequilibrium Plasmas ◽  
Rf Energy

Cost Effective, Scalable Optically Pumped Molecular Laser

2001 ◽  
Author(s):  
Jeff Nicholson ◽  
David Neumann ◽  
Wolfgang Rudolph
Keyword(s):  
Cost Effective ◽  
Optically Pumped ◽  
Molecular Laser ◽  
Optically Pumped Molecular Laser

LBE Flows in Disordered Media

2018 ◽  
Author(s):  
Sauro Succi
Keyword(s):  
Porous Media ◽  
Fluid Mechanics ◽  
Condensed Matter ◽  
Disordered Media ◽  
Environmental Sciences ◽  
Science And Engineering ◽  
Particle Trajectories ◽  
Irregular Geometries ◽  
Numerical Tool ◽  
Bounce Back

The study of transport phenomena in disordered media is a subject of wide interdisciplinary concern, with many applications in fluid mechanics, condensed matter, life and environmental sciences as well. Flows through grossly irregular (porous) media is a specific fluid mechanical application of great practical value in applied science and engineering. It is arguably also one of the applications of choice of the LBE methods. The dual field–particle character of LBE shines brightly here: the particle-like nature of LBE (populations move along straight particle trajectories) permits a transparent treatment of grossly irregular geometries in terms of elementary mechanical events, such as mirror and bounce-back reflections. These assets were quickly recognized by researchers in the field, and still make of LBE (and eventually LGCA) an excellent numerical tool for flows in porous media, as it shall be discussed in this Chapter.

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