Связь релаксации собственного стимулированного пикосекундного излучения GaAs с характерным временем остывания носителей заряда

During the powerful picosecond optical pumping of a thin (~ 1 µm) GaAs layer, a stimulated intense (up to 1 GW/cm^2) picosecond emission appeared. As was found, for a fixed density of the pump pulse energy, with an increase of its diameter the characteristic picosecond time τr of the emission and carrier density n relaxation increases. Due to interrelation of the density and the temperature of the carriers at high-intensity emission (in the saturation state of the emission amplification), time τr is associated with the characteristic temperature relaxation time τT of the photo-pumped carriers, which was determined earlier theoretically with the emission-caused carrier heating taken into account. The corresponding analytical expressions for τr as a functions of τT are consistent with the above experimental results.

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Антикорреляция интенсивности стимулированного пикосекундного излучения GaAs и характерного времени остывания носителей заряда

Физика и техника полупроводников ◽

10.21883/ftp.2020.01.48764.9209 ◽

2020 ◽

Vol 54 (1) ◽

pp. 25

Author(s):

Н.Н. Агеева ◽

И.Л. Броневой ◽

Д.Н. Забегаев ◽

А.Н. Кривоносов

Keyword(s):

Relaxation Time ◽

Energy Density ◽

Emission Intensity ◽

Pump Beam ◽

Optical Pumping ◽

Pump Energy ◽

Gaas Layer ◽

Charge Carriers ◽

Characteristic Relaxation Time ◽

Maximum Emission

During the powerful picosecond optical pumping, intense stimulated picosecond emission arises in a thin GaAs layer. It was found that, firstly, the maximum emission intensity decreases with increasing diameter of the pump beam (the pump energy density is fixed). Secondly, this dependence is anticorrelated with the dependence on the diameter of the characteristic relaxation time of the emission. And this time, in turn, is associated with the characteristic cooling time of charge carriers, which is slowed down due to heating of the carriers by emission. As a result, the autocorrelation indicated in the title is revealed.

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High-Power Low-Threshold Optically Pumped Type-ll Quantum-Well Lasers

MRS Proceedings ◽

10.1557/proc-484-107 ◽

1997 ◽

Vol 484 ◽

Author(s):

Chih-Hsiang Lin ◽

S. J. Murry ◽

Rui Q. Yang ◽

S. S. Pei ◽

H. Q. Le ◽

...

Keyword(s):

Quantum Well ◽

Output Power ◽

Optical Pumping ◽

Internal Quantum Efficiency ◽

Characteristic Temperature ◽

Stimulated Emission ◽

Free Carrier Absorption ◽

Type Ii ◽

Optically Pumped ◽

Internal Loss

AbstractStimulated emission in InAs/InGaSb/InAs/AlSb type-II quantum-well (QW) lasers was observed up to room temperature at 4.5 μm, optically pumped by a pulsed 2-μm Tm:YAG laser. The absorbed threshold peak pump intensity was only 1.1 kW/cm2 at 300 K, with a characteristic temperature T0 of 61.6 K for temperatures up to 300 K. We will also study the effects of internal loss on the efficiency and output power for type-II QW lasers via optical pumping. Using a 0.98-μm InGaAs linear diode array, the devices exhibited an internal quantum efficiency of 67% at temperatures up to 190 K, and was capable of < 1. 1-W peak output power per facet in 6-μs pulses at 85 K. The internal loss of the devices exhibited an increase from 18 cm−1 near 70 K to ∼ 60–100 cm−1 near 180 K, which was possibly due to inter-valence band free carrier absorption.

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Carrier density depinning above threshold in semiconductor lasers: effects of carrier heating and spectral hole burning

IEE Proceedings - Optoelectronics ◽

10.1049/ip-opt:19971184 ◽

1997 ◽

Vol 144 (4) ◽

pp. 209-212 ◽

Cited By ~ 3

Author(s):

C.-Yi Tsai ◽

C.-Yao Tsai

Keyword(s):

Semiconductor Lasers ◽

Carrier Density ◽

Hole Burning ◽

Spectral Hole Burning ◽

Carrier Heating ◽

Spectral Hole

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Multiple-pulse spin locking in nanofluids

RSC Advances ◽

10.1039/c5ra06439b ◽

2015 ◽

Vol 5 (55) ◽

pp. 44247-44257 ◽

Cited By ~ 6

Author(s):

Gregory B. Furman ◽

Shaul D. Goren ◽

Victor M. Meerovich ◽

Vladimir L. Sokolovsky

Keyword(s):

Relaxation Time ◽

Water Molecules ◽

Nuclear Spins ◽

Multiple Pulse ◽

Spin Locking ◽

Analytical Expressions

The multiple pulse spin locking dynamics of the nuclear spins in nanofluids was studied. Oriented (a) and disoriented (b) nanocavities containing water molecules (c) were considered. Analytical expressions for the magnetization and the relaxation time were obtained.

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Thermal equilibration of samples for neutron scattering

Journal of Applied Crystallography ◽

10.1107/s0021889812048388 ◽

2013 ◽

Vol 46 (1) ◽

pp. 279-285 ◽

Cited By ~ 4

Author(s):

Tobias K. Herman ◽

Sarah C. Parks ◽

Julia Scherschligt

Keyword(s):

Relaxation Time ◽

Neutron Scattering ◽

Material Properties ◽

Thermal Relaxation ◽

Sample Cell ◽

Time Constants ◽

Thermal Equilibration ◽

Temperature Relaxation ◽

Relaxation Time Constants ◽

Selection Of

Temperature relaxation and equilibration of samples for neutron scattering was investigated in a selection of samples and sample cells within the range of 5–300 K. A simple model was developed that relates thermal relaxation time constants to material properties of the sample and sample cell. This model should facilitate extension of this study to prediction of thermal behavior in other systems.

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Dehydration in the tropical tropopause layer estimated from the water vapor match

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acpd-13-633-2013 ◽

2013 ◽

Vol 13 (1) ◽

pp. 633-688 ◽

Cited By ~ 1

Author(s):

Y. Inai ◽

F. Hasebe ◽

M. Fujiwara ◽

M. Shiotani ◽

N. Nishi ◽

...

Keyword(s):

Relaxation Time ◽

Water Vapor ◽

Relative Humidity ◽

Western Pacific ◽

Dehydration Process ◽

Saturation State ◽

Air Mass ◽

Tropical Tropopause Layer ◽

Tropical Tropopause ◽

The Western Pacific

Abstract. Variation in stratospheric water vapor is controlled mainly by the dehydration process in the tropical tropopause layer (TTL) over the western Pacific; however, this process is poorly understood. To address this shortcoming, in this study the match method is applied to quantify the dehydration process in the TTL over the western Pacific. The match pairs are sought from the Soundings of Ozone and Water in the Equatorial Region (SOWER) campaign network observations using isentropic trajectories. For the pairs identified, extensive screening procedures are performed to verify the representativeness of the air parcel and the validity of the isentropic treatment, and to check for possible water injection by deep convection, consistency between the sonde data and analysis field, and conservation of the ozone content. Among the pairs that passed the screening test, we found some cases corresponding to the first quantitative value of dehydration associated with horizontal advection in the TTL. The statistical features of dehydration for the air parcels advected in the lower TTL are derived from the match pairs. Match analysis indicates that ice nucleation starts before the relative humidity with respect to ice (RHice) reaches 207 ± 81% (1σ) and that the air mass is dehydrated until RHice reaches 83 ± 30% (1σ). The efficiency of dehydration is estimated as the relaxation time required for the relative humidity of the supersaturated air parcel to approach the saturation state. This is empirically estimated from the match pairs as the quantity that reproduces the second water vapor observation, given the first observed water vapor amount and the history of the saturation mixing ratio of the match air mass exposed during the advection. The relaxation time is found to range from 2 to 3 h, which is consistent with previous studies.

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Magnetooptical studies and stimulated emission in narrow gap HgTe/CdHgTe structures in the very long wavelength infrared range

Физика и техника полупроводников ◽

10.21883/ftp.2018.04.45813.02 ◽

2018 ◽

Vol 52 (4) ◽

pp. 464

Author(s):

V.V. Rumyantsev ◽

L.S. Bovkun ◽

A.M. Kadykov ◽

M.A. Fadeev ◽

A.A. Dubinov ◽

...

Keyword(s):

Quantum Wells ◽

Optical Pumping ◽

High Energy ◽

Stimulated Emission ◽

Infrared Range ◽

Recombination Mechanism ◽

Carrier Heating ◽

Long Wavelength ◽

Carrier Recombination ◽

Long Wavelength Infrared

AbstractWe investigate the prospects of HgTe/HgCdTe quantum wells for long-wavelength interband lasers (λ = 15–30 μm). The properties of stimulated emission (SE) and magnetoabsorbtion data of QWs structures with wide-gap HgCdTe dielectric waveguide provide an insight on dominating non-radiative carrier recombination mechanism. It is shown that the carrier heating under intense optical pumping is the main factor limiting the SE wavelength and intensity, since the Auger recombination is greatly enhanced when carriers populate high energy states in the valence band.

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Calculated Spin-lattice Relaxation of 103Ru Compared with Low Temperature Quadrupole Orientation Measurements

Zeitschrift für Naturforschung A ◽

10.1515/zna-1994-1-260 ◽

1994 ◽

Vol 49 (1-2) ◽

pp. 395-400 ◽

Cited By ~ 1

Author(s):

R. Markendorf

Keyword(s):

Relaxation Time ◽

Low Temperature ◽

Reference Value ◽

Lattice Relaxation ◽

Lattice Relaxation Time ◽

Spin Lattice Relaxation ◽

Axially Symmetric ◽

Quadrupole Field ◽

Spin Lattice ◽

Temperature Relaxation

Abstract The spin-lattice relaxation time T1 in 103Ru has been determined on the basis of the Dirac theory and strict relativistic band structure calculations. The low temperature relaxation time T(of 103Ru in an axially symmetric quadrupole field and the quadrupole moment Q have been measured by Green and Stone using the technique of low temperature quadrupole orientation. For the usual reference value T1 T, which corresponds to relaxation in a Zeeman spectrum, they obtain 39(6) sK, which exceeds our value by 134%. This large discrepancy is attributed to the fact that the spin relaxation by direct quadrupole scattering of conduction electrons, the so-called Mitchell contribution, is dominant. According to our calculations it amounts to 81% of the total relaxation rate. This contribution could not be included in the evaluation of the experimental data.

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High-Sensitivity High-Resolution Full-Wafer Imaging of the Properties of Large n-Type SiC Using the Relative Reflectance of Two Terahertz Waves

Materials Science Forum ◽

10.4028/www.scientific.net/msf.778-780.491 ◽

2014 ◽

Vol 778-780 ◽

pp. 491-494 ◽

Cited By ~ 2

Author(s):

Akihide Hamano ◽

Seigo Ohno ◽

Hiroaki Minamide ◽

Hiromasa Ito ◽

Yoshiyuki Usuki

Keyword(s):

Silicon Carbide ◽

Relaxation Time ◽

Carrier Density ◽

High Sensitivity ◽

Thz Imaging ◽

Terahertz Waves ◽

Large N ◽

Imaging Results ◽

Standard Values ◽

Precision And Accuracy

THz imaging was performed in 2 s intervals with 1 mm resolution on a 3 in., 0.42 mm thick, as-cut n-type Silicon Carbide wafer. Carrier density, relaxation time, mobility, and resistivity obtained from imaging results are 0.91 × 1018 cm-3, 4.36 × 10-14 s, 218 cm2V-1s-1, and 3.14 × 10-2 Ωcm, respectively. Compared with the standard values provided by the manufacturers, the results suggest that THz imaging has reliable precision and accuracy.

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