scholarly journals Effects of Variation of Quantum Well Numbers on Gain Characteristics of Type-I InGaAsP/InP Nano-heterostructure

2017 ◽  
Vol 6 (3) ◽  
pp. 301-310
Author(s):  
S. G. Anjum ◽  
Sandhya K. ◽  
A. B. Khan ◽  
A. M. Khan ◽  
M. J. Siddiqui ◽  
...  
Keyword(s):  
Quantum Well ◽  
Quantum Wells ◽  
Carrier Density ◽  
Multiple Quantum ◽  
Type I ◽  
Long Distance ◽  
Single Quantum Well ◽  
Lasing Wavelength ◽  
Material Gain ◽  
Distance Communication

This paper reports the effects of variation of number of quantum wells in material gain characteristics and lasing wavelength of step index separately confined type-I InGaAsP/InP lasing nano-heterostructure for different carrier concentrations at room temperature in TE (Transverse Electric) mode of polarization. Peak material gain is found to be highest when the number of quantum well is one in the structure. However, for the case of 3QWs, 5QWs and 7QWs, it is almost same at a particular carrier density. Lasing wavelength at peak material gain considerably increases as the number of quantum well layers vary from single quantum well layer to three quantum well layers in the active region and after that it will remain almost same by any further increase in number of quantum wells for a particular carrier density. Furthermore, negative gain condition in the material gain spectra exists in the case of multiple quantum wells only at carrier concentration of 2×1018/cm3. The results suggest that the proposed nano-heterostructure is highly suitable as a light source in fiber optic links for long distance communication.

Stimulated Emission from Single- and Multiple-Quantum-Well GaN-AlGaN Separate-Confinement Heterostructures

1996 ◽  
Vol 449 ◽  
Author(s):  
D. A. S. Loeber ◽  
N. G. Anderson ◽  
J. M. Redwing ◽  
J. S. Flynn ◽  
G. M. Smith ◽  
...  
Keyword(s):  
Quantum Well ◽  
Quantum Wells ◽  
Optical Pumping ◽  
Multiple Quantum Well ◽  
Emission Spectra ◽  
Stimulated Emission ◽  
Emission Characteristics ◽  
Multiple Quantum ◽  
Photoluminescence Properties ◽  
Single Quantum Well

ABSTRACTStimulated emission characteristics are examined for GaN-AlGaN separate-confinement quantum-well heterostructures grown by MOVPE on 4H-SiC substrates. We specifically focus on comparison of structures with different quantum well active region designs. Polarization resolved edge emission spectra and stimulated emission thresholds are obtained under optical pumping using a stripe excitation geometry. Stimulated emission characteristics are studied as a function of the number of quantum wells in the structure, and are correlated with surface photoluminescence properties. We find reduced stimulated emission thresholds and increased surface photoluminescence intensities as the number of quantum wells is reduced, with the best results obtained for a single-quantum-well structure. These results should provide useful information for the design of GaN-based quantum well lasers.

GaAs–AlGaAs multiple-quantum-well lasers for monolithic integration with optical modulators

1991 ◽  
Vol 69 (3-4) ◽  
pp. 491-496 ◽  
Author(s):  
F. Chatenoud ◽  
K. M. Dzurko ◽  
M. Dion ◽  
D. Moss ◽  
R. Barber ◽  
...  
Keyword(s):  
Quantum Well ◽  
Quantum Wells ◽  
Cavity Length ◽  
Multiple Quantum Well ◽  
Monolithic Integration ◽  
Quantum Well Lasers ◽  
Multiple Quantum ◽  
Optical Modulators ◽  
Single Quantum Well ◽  
Quantum Well Structures

Calculations of multiple-quantum-well laser threshold current show that a common minimum current value exists for each number of wells, at an appropriate cavity length. This optimum cavity length decreases rapidly with increasing number of wells, for instance from about 300 to 110 μm for one to three wells. Granded-index separate-confinement heterostructure (GRINSCH) lasers with 1–10 quantum wells, grown by molecular beam epitaxy, show consistently low threshold currents that agree well with theoretical predictions. Lasing is achieved at 160 A cm−2 and 4.6 mA for broad-area and ridge waveguide single-quantum-well devices, respectively. The field-dependent electroabsorption of these devices when operating as wave-guide modulators indicates good modulation properties for one and three quantum-well structures, with on:off ratios above 55 at lasing wavelength. The behavior becomes more complex with increasing number of wells. This systematic study of discrete multiple-quantum-well lasers and modulators demonstrates that GRINSCH structures with 1–3 wells are the most suitable for monolithic integration. Design rules for the laser cavity are also presented for numbers of wells ranging from 1 to 10.

Photoluminescence In Strain Compensated Siisigec Multiple Quantum Wells

1998 ◽  
Vol 533 ◽  
Author(s):  
R. Hartmann ◽  
U. Gennser ◽  
D. Grützmacher ◽  
H. Sigg ◽  
E. Müller ◽  
...  
Keyword(s):  
Quantum Well ◽  
Quantum Wells ◽  
Band Gap ◽  
Valence Band ◽  
Band Alignment ◽  
Multiple Quantum ◽  
Type I ◽  
Strain Compensation ◽  
Quantum Well States ◽  
Good Agreement

AbstractThe effect of strain compensation on the band gap and band alignment of Si/SiGeC MQWs is studied by photoluminescence (PL) spectroscopy. Evidence for type-I band alignment of strain reduced SiGeC MQWs is found. Values for the conduction and valence band offsets are given. A band gap reduction for exactly strain compensated SiGeC compared to compressive SiGeC is observed. This behavior is interpreted in terms of strain induced splitting and confinement shifts of the quantum well states. A good agreement between the model and the PL data is obtained.

scholarly journals Влияние конструкции активной области и волновода на характеристики лазеров на основе структур квантовые ямы-точки InGaAs/GaAs

2021 ◽  
Vol 55 (3) ◽  
pp. 256
Author(s):  
Ю.М. Шерняков ◽  
Н.Ю. Гордеев ◽  
А.С. Паюсов ◽  
А.А. Серин ◽  
Г.О. Корнышов ◽  
...  
Keyword(s):  
Quantum Well ◽  
Quantum Wells ◽  
Ground State ◽  
Cavity Length ◽  
Blue Shift ◽  
Optical Confinement ◽  
Single Quantum Well ◽  
Lasing Wavelength ◽  
Optical Region ◽  
Emitting Lasers

We study edge-emitting lasers with the active area based on novel InGaAs/GaAs quantum heterostructures of transitional dimensionality referred to as quantum well-dots, which are intermediate in properties between quantum wells and quantum dots. We show that the rate of the lasing wavelength blue-shift occurring with the reduction in cavity length decreases with an increase in the number of quantum well-dot layers in the active region and the optical confinement factor. In the laser based on 10 quantum well-dot layers, the position of the lasing wavelength remains in the optical region corresponding to the emission from the ground state down to the cavity lengths as short as 100 μm. In the devices based on a single quantum well-dot layer and/or with low optical confinement factor, lasing directly switches from the ground state to the GaAs waveguide states omitting excited state lasing with decrease in cavity length below 200 μm. Such an effect has not been observed in quantum well and quantum dot lasers and is attributed to the abnormally low density of excited states in quantum well-dots.

Photoluminescence investigation of InGaN/GaN single quantum well and multiple quantum wells

1998 ◽  
Vol 73 (24) ◽  
pp. 3571-3573 ◽  
Author(s):  
T. Wang ◽  
D. Nakagawa ◽  
J. Wang ◽  
T. Sugahara ◽  
S. Sakai
Keyword(s):  
Quantum Well ◽  
Quantum Wells ◽  
Multiple Quantum Wells ◽  
Multiple Quantum ◽  
Single Quantum ◽  
Single Quantum Well

Characterisation of multilayer materials using a position-sensitive atom probe

1990 ◽  
Vol 48 (4) ◽  
pp. 624-625
Author(s):  
RAD Mackenzie ◽  
G D W Smith ◽  
A. Cerezo ◽  
J A Liddle ◽  
CRM Grovenor ◽  
...  
Keyword(s):  
Quantum Well ◽  
Quantum Wells ◽  
Spatial Information ◽  
Chemical Vapour ◽  
Atom Probe ◽  
Organic Chemical ◽  
Growth Stages ◽  
Multiple Quantum ◽  
Quartz Wool ◽  
Position Sensitive

The position sensitive atom probe (POSAP), described briefly elsewhere in these proceedings, permits both chemical and spatial information in three dimensions to be recorded from a small volume of material. This technique is particularly applicable to situations where there are fine scale variations in composition present in the material under investigation. We report the application of the POSAP to the characterisation of semiconductor multiple quantum wells and metallic multilayers.The application of devices prepared from quantum well materials depends on the ability to accurately control both the quantum well composition and the quality of the interfaces between the well and barrier layers. A series of metal organic chemical vapour deposition (MOCVD) grown GaInAs-InP quantum wells were examined after being prepared under three different growth conditions. These samples were observed using the POSAP in order to study both the composition of the wells and the interface morphology. The first set of wells examined were prepared in a conventional reactor to which a quartz wool baffle had been added to promote gas intermixing. The effect of this was to hold a volume of gas within the chamber between growth stages, leading to a structure where the wells had a composition of GalnAsP lattice matched to the InP barriers, and where the interfaces were very indistinct. A POSAP image showing a well in this sample is shown in figure 1. The second set of wells were grown in the same reactor but with the quartz wool baffle removed. This set of wells were much better defined, as can be seen in figure 2, and the wells were much closer to the intended composition, but still with measurable levels of phosphorus. The final set of wells examined were prepared in a reactor where the design had the effect of minimizing the recirculating volume of gas. In this case there was again further improvement in the well quality. It also appears that the left hand side of the well in figure 2 is more abrupt than the right hand side, indicating that the switchover at this interface from barrier to well growth is more abrupt than the switchover at the other interface.

Photoluminescence Studies of [(CdSe)1(ZnSe)2]9-ZnSeTe Multiple Quantum Wells Under High Pressure

1994 ◽  
Vol 358 ◽  
Author(s):  
Z.P. Wang ◽  
Z.X. Liu ◽  
H.X. Han ◽  
J.Q. Zhang ◽  
G.H. Li ◽  
...  
Keyword(s):  
High Pressure ◽  
Quantum Wells ◽  
Liquid Nitrogen Temperature ◽  
Multiple Quantum Wells ◽  
Multiple Quantum ◽  
Type I ◽  
Short Period ◽  
Heavy Hole Subband ◽  
Photoluminescence Studies ◽  
Increasing Temperature

ABSTRACTWe have performed photoluminescence (PL) measurements at liquid nitrogen temperature under high pressure up to 5.5 GPa and in the temperature range 10-300 K at atmospheric pressure on {(ZnSe)30(ZnSe0.92Te0.08)30(ZnSe)30[(CdSe)1(ZnSe)2]9}x5 multiple quantum wells. The PL peaks, EB, E1 and Ew corresponding to the band edge luminescence in ZnSe barrier layer, the transitions from the first conduction subband to the heavy-hole subband in ZnSe0.92Te0.08 layers and [(CdSe)1(ZnSe)2]9 ultra short period superlattice quantum well (SPSLQW) layers have been observed. Experimental results show that ZnSe0.92Te0.08/ZnSe forms a type-I superlattice (SL) in contrast to the type-II ZnSe/ZnTe SL. The pressure coefficients of the EB, E1 and Ew exciton peaks have been determined as 67, 63 and 56 meV/GPa, respectively. With increasing temperature (or pressure), the E1 peak-intensity drastically decreases which is attributed to the thermal effect (or the appearance of many defects in ZnSe0.92Te0.08 under higher pressure).

Sign in / Sign up

Export Citation Format

Share Document