scholarly journals Влияние внутренних оптических потерь на генерацию стимулированного излучения в среднем ИК диапазоне в волноводных гетероструктурах с квантовыми ямами HgCdTe/CdHgTe

2021 ◽  
Vol 55 (10) ◽  
pp. 922
Author(s):  
В.В. Уточкин ◽  
А.А. Дубинов ◽  
М.А. Фадеев ◽  
В.В. Румянцев ◽  
Н.Н. Михайлов ◽  
...  
Keyword(s):  
Optical Absorption ◽  
Quantum Wells ◽  
Wavelength Range ◽  
Short Wavelength ◽  
Stimulated Emission ◽  
Long Wavelength

We study two heterostructures with an array of 10 HgCdTe/CdHgTe quantum wells, grown within a single technological series and designed to generate stimulated emission (SE) in the 20 – 30 µm wavelength range. In the more short-wavelength structure we obtain SE at the wavelength λ ~ 23.9 µm at 10 K, while no SE was obtained in the more long-wavelength structure. We calculate optical absorption in passive layers for both structures and show it to be higher in the more long-wavelength structure. Finally, we consider several ways to minimize absorption influence on SE generation.

scholarly journals Magnetic compass orientation in European robins is dependent on both wavelength and intensity of light

2002 ◽  
Vol 205 (24) ◽  
pp. 3845-3856 ◽  
Author(s):  
Rachel Muheim ◽  
Johan Bäckman ◽  
Susanne Åkesson
Keyword(s):  
Transition Zone ◽  
Wavelength Range ◽  
Short Wavelength ◽  
Monochromatic Light ◽  
Magnetic Compass ◽  
Autumn Migration ◽  
Compass Orientation ◽  
Long Wavelength ◽  
Magnetic Compass Orientation ◽  
And Shifts

SUMMARYMagnetic compass orientation in birds has been shown to be light dependent. Results from behavioural studies indicate that magnetoreception capabilities are disrupted under light of peak wavelengths longer than 565 nm, and shifts in orientation have been observed at higher light intensities(43-44×1015 quanta s-1 m-2). To investigate further the function of the avian magnetic compass with respect to wavelength and intensity of light, we carried out orientation cage experiments with juvenile European robins, caught during their first autumn migration,exposed to light of 560.5 nm (green), 567.5 nm (green-yellow) and 617 nm (red)wavelengths at three different intensities (1 mW m-2, 5 mW m-2 and 10 mW m-2). We used monochromatic light of a narrow wavelength range (half bandwidth of 9-11 nm, compared with half bandwidths ranging between 30 nm and 70 nm used in other studies) and were thereby able to examine the magnetoreception mechanism in the expected transition zone between oriented and disoriented behaviour around 565 nm in more detail. We show (1) that European robins show seasonally appropriate migratory directions under 560.5 nm light, (2) that they are completely disoriented under 567.5 nm light under a broad range of intensities, (3) that they are able to orient under 617 nm light of lower intensities, although into a direction shifted relative to the expected migratory one, and (4) that magnetoreception is intensity dependent, leading to disorientation under higher intensities. Our results support the hypothesis that birds possess a light-dependent magnetoreception system based on magnetically sensitive,antagonistically interacting spectral mechanisms, with at least one high-sensitive short-wavelength mechanism and one low-sensitive long-wavelength mechanism.

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

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.

Investigation of HgCdTe waveguide structures with quantum wells for long-wavelength stimulated emission

2017 ◽  
Vol 51 (12) ◽  
pp. 1557-1561 ◽  
Author(s):  
V. V. Rumyantsev ◽  
A. M. Kadykov ◽  
M. A. Fadeev ◽  
A. A. Dubinov ◽  
V. V. Utochkin ◽  
...  
Keyword(s):  
Quantum Wells ◽  
Stimulated Emission ◽  
Long Wavelength

Long-wavelength stimulated emission and carrier lifetimes in HgCdTe-based waveguide structures with quantum wells

2016 ◽  
Vol 50 (12) ◽  
pp. 1651-1656 ◽  
Author(s):  
V. V. Rumyantsev ◽  
M. A. Fadeev ◽  
S. V. Morozov ◽  
A. A. Dubinov ◽  
K. E. Kudryavtsev ◽  
...  
Keyword(s):  
Quantum Wells ◽  
Stimulated Emission ◽  
Long Wavelength ◽  
Carrier Lifetimes

Light Emission Properties of GaN-Based Double Heterostructures and Quantum Wells

1995 ◽  
Vol 395 ◽  
Author(s):  
D.A.S. Loeber ◽  
J.M. Redwing ◽  
N.G. Anderson ◽  
M.A. Tischler
Keyword(s):  
Quantum Well ◽  
Quantum Wells ◽  
Stimulated Emission ◽  
Pump Light ◽  
Band Edge Emission ◽  
Emission Characteristics ◽  
Nitrogen Laser ◽  
Edge Emission ◽  
Edge Luminescence ◽  
Double Heterostructures

ABSTRACTEdge emission characteristics of optically pumped GaN-AlGaN double heterostructures and quantum wells are examined. The samples, which were grown by metalorganic vapor phase epitaxy, are photoexcited with light from a pulsed nitrogen laser. The pump light is focused to a narrow stripe on the sample surface, oriented perpendicular to a cleaved edge, and the edge luminescence is collected and analyzed. We first compare emission characteristics of highly excited GaN-AlGaN double heterostructures grown simultaneously on SiC and sapphire substrates. Polarization resolved spectral properties of edge luminescence from both structures is studied as a function of pump intensity and excitation stripe length. Characteristics indicative of stimulated emission are observed, particularly in the sample grown on SiC. We then present results demonstrating laser emission from a GaN-AlGaN separate-confinement quantum-well heterostructure. At high pump intensities, band edge emission from the quantum well exhibits five narrow (∼1 Å) modes which are evenly spaced by 10Å to within the resolution of the spectrometer. This represents the first demonstration of laser action in a GaN-based quantum-well structure.

LINEAR AND NONLINEAR INTERSUBBAND OPTICAL ABSORPTION OF FINITE AND INFINITE SEMI-PARABOLIC QUANTUM WELLS

2011 ◽  
Vol 25 (07) ◽  
pp. 497-507 ◽  
Author(s):  
M. J. KARIMI ◽  
A. KESHAVARZ ◽  
A. POOSTFORUSH
Keyword(s):  
Refractive Index ◽  
Optical Properties ◽  
Optical Absorption ◽  
Quantum Well ◽  
Quantum Wells ◽  
Resonant Peak ◽  
Energy Eigenvalues ◽  
Finite Case ◽  
Infinite Case ◽  
Index Changes

In this work, the optical absorption coefficients and the refractive index changes for the infinite and finite semi-parabolic quantum well are calculated. Numerical calculations are performed for typical GaAs / Al x Ga 1-x As semi-parabolic quantum well. The energy eigenvalues and eigenfunctions of these systems are calculated numerically. Optical properties are obtained using the compact density matrix approach. Results show that the energy eigenvalues and the matrix elements of the infinite and finite cases are different. The calculations reveal that the resonant peaks of the optical properties of the finite case occur at lower values of the incident photon energy with respect to the infinite case. Results indicate that the maximum value of the refractive index changes for the finite case are greater than that of the infinite case. Our calculations also show that in contrast to the infinite case, the resonant peak value of the total absorption coefficient in the case of the finite well is a non-monotonic function of the semi-parabolic confinement frequency.

Ultraviolet Stimulated Emission From Optically Pumped AlGaN/AlGaN Multiple Quantum Wells on Pulsed Laterally Overgrown $a$-Plane GaN

2011 ◽  
Vol 4 (8) ◽  
pp. 082103 ◽  
Author(s):  
Mohamed Lachab ◽  
Krishnan Balakrishnan ◽  
Bin Zhang ◽  
Joe Dion ◽  
Qhalid Fareed ◽  
...  
Keyword(s):  
Quantum Wells ◽  
Stimulated Emission ◽  
Multiple Quantum Wells ◽  
Multiple Quantum ◽  
Optically Pumped
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