Vibrational population-inversion and stimulated emission from the continuous-mixing of chemical reagents

1967 ◽  
Vol 24 (4) ◽  
pp. 208-210 ◽  
Author(s):  
K.G. Anlauf ◽  
D.H. Maylotte ◽  
P.D. Pacey ◽  
J.C. Polanyi
Keyword(s):  
Population Inversion ◽  
Stimulated Emission ◽  
Continuous Mixing ◽  
Chemical Reagents ◽  
Vibrational Population

EXCITED STATE PHOTOLUMINESCENCE IN STEPPED InGaAs/AlGaAs QUANTUM WELLS UNDER PICOSECOND EXCITATION

2003 ◽  
Vol 02 (06) ◽  
pp. 427-435
Author(s):  
V. A. SHALYGIN ◽  
L. E. VOROBJEV ◽  
V. Yu. PANEVIN ◽  
D. A. FIRSOV ◽  
S. HANNA ◽  
...  
Keyword(s):  
Excited State ◽  
Quantum Wells ◽  
Special Interest ◽  
Population Inversion ◽  
Auger Recombination ◽  
Stimulated Emission ◽  
Energy Structure ◽  
Electron Hole ◽  
Picosecond Excitation ◽  
Electron Energy Structure

The technique of photoluminescence (PL) studies based on intense picosecond excitation of electron–hole pairs is applied to investigate the electron energy structure including the positions of high-lying excited levels in stepped quantum wells (QWs). The spectra of PL in regimes of spontaneous and stimulated emission are studied under different excitation levels and light polarizations. Of special interest are intense photoluminescence signals from excited subbands. The feasibility of a e3–e2 intersubband population inversion in stepped QWs is demonstrated and the influence of Auger recombination was examined.

Spontaneous and Stimulated Intersubband Emission Under Optical Pumping

1996 ◽  
Vol 450 ◽  
Author(s):  
P. Boucaud ◽  
S. Sauvage ◽  
O. Gauthier-Lafaye ◽  
Z. Moussa ◽  
F.-H. Julien ◽  
...  
Keyword(s):  
Quantum Wells ◽  
Free Electron Laser ◽  
Population Inversion ◽  
Laser Emission ◽  
Optical Pumping ◽  
Stimulated Emission ◽  
Mid Infrared ◽  
Asymmetric Quantum ◽  
Waveguide Length ◽  
Subband Energy

ABSTRACTWe have investigated the mid-infrared spontaneous and stimulated emission between confined subbands in the conduction band of GaAs/AlGaAs quantum wells. The carriers which give rise to the intersubband emission are excited in the upper subbands using an intersubband optical pumping in coupled asymmetric quantum wells. The quantum wells are designed using phonon engineering in order to obtain population inversion between the second and first excited subband. This is obtained by adjusting the subband energy spacing between E2 and E1 close to the optical phonon energy which in turn allows an efficient relaxation. We have first observed intersubband spontaneous emission between E3 and E2 at 14 μm using an intersubband pumping with a CO2 laser in resonance with the E1-E3 transition. In a second set of experiments, the quantum wells are embedded in an infrared waveguide. We have measured the stimulated intersubband gain using a picosecond two-color free electron laser. The first color bleaches the E1-E3 transition and provides the population inversion. The intersubband stimulated gain is measured versus the waveguide length and photon energy. Stimulated gains ≈ 80 cm−1 are reported thus demonstrating that laser emission under optical pumping appears feasible in optimized structures. Finally, we show that intersubband emission can also be observed in quantum wells using an interband optical pumping.

Production of Vibrationally Excited Carbon Monoxide by the Reaction of Oxygen Atoms with Acetylene, Methylacetylene, and Methane

1973 ◽  
Vol 51 (3) ◽  
pp. 451-455
Author(s):  
S. J. Arnold ◽  
G. H. Kimbell
Keyword(s):  
Carbon Monoxide ◽  
Electrical Discharge ◽  
Population Inversion ◽  
Continuous Wave ◽  
Microwave Discharge ◽  
Vibrationally Excited ◽  
Vibrational Population ◽  
Oxygen Atoms

Infrared chemiluminescence attributed to the first overtone of CO was observed when either C2H2 or was introduced into a stream of oxygen which had been passed through a microwave discharge. The addition of vibrationally cold CO to these systems was found to produce a vibrational population inversion in the chemically formed CO. CO first overtone emission was not observed when CH4 was introduced into a similar stream of oxygen unless the CH4 had been subjected to a microwave discharge. These observations are used to clarify the mechanisms governing the formation of CO in continuous wave air–helium–hydrocarbon electrical discharge lasers.

scholarly journals Химический сдвиг и энергия обменного взаимодействия 1s состояний доноров магния в кремнии. Возможность стимулированного излучения

2019 ◽  
Vol 53 (9) ◽  
pp. 1263
Author(s):  
В.Н. Шастин ◽  
Р.Х. Жукавин ◽  
К.А. Ковалевский ◽  
В.В. Цыпленков ◽  
В.В. Румянцев ◽  
...  
Keyword(s):  
Experimental Data ◽  
Population Inversion ◽  
Elevated Temperatures ◽  
Stimulated Raman Scattering ◽  
Stimulated Emission ◽  
Fano Resonances ◽  
Relaxation Rates ◽  
Specific Mechanism ◽  
S States ◽  
Mg Doped

AbstractThe results of experiments aimed at the observation of split 1 s states in Mg-doped Si are reported. From the results, it is possible to determine the chemical shift and exchange interaction energy of a neutral Mg donor in Si. The position of the 1 s ( E ), 1 s ( T _2), and 2 s ( A _1) parastates determines the possibility for attaining population inversion and the specific mechanism of stimulated Raman scattering. The energy of the 1 s ( T _2) parastate is determined from the position of the Fano resonances in the photoconductivity spectrum of Si:Mg at T = 4 K, and the energies of the 1 s ( T _2) and 1 s ( E ) orthostates from the transmittance spectra at elevated temperatures. On the basis of the experimental data, the relaxation rates are estimated, and the possible mechanisms of stimulated emission are analyzed.

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