Influence of doping on gain characteristics of GaInNAs/GaAs quantum well lasers (original) (raw)
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Journal of Applied Physics, 2010
The optical gain and radiative current density of GaInNAs/GaAs/AlGaAs separate confinement heterostructure quantum well ͑QW͒ lasers with an emission wavelength of 1.3 m have been theoretically investigated. The effect of carrier leakage from the GaInNAs QW to the GaAs waveguide layer is studied, and its influence on the optical gain and radiative current density is identified. The hole filling caused by an injected carrier has a strong impact on the optical gain and radiative current density, while the effect of electron filling is negligible, reflecting the smaller band-gap discontinuity in the valence band than in the conduction band. Hole occupation in the waveguide layer decreases the optical gain, and increases the radiative and threshold current densities of the laser. Our calculated threshold current density ͑659.6 A / cm 2 ͒ at T = 300 K is in good agreement with the experimental value ͑650.9 A / cm 2 ͒ reported in literature ͓R.
Optical properties of GaInNAs/GaAs quantum wells
Solid-State Electronics, 2003
We report the results of our studies of optical and electro-optic properties of GaInNAs/GaAs single quantum wells grown by chemical beam epitaxy. The quantum wells have been characterised by scanning transmission electron microscopy and energy dispersive X-ray analysis. Photoluminescence measurements from sequentially grown GaInAs and GaInNAs quantum wells were carried out between 4 K and room temperature. A significant difference in the temperature dependence of GaInNAs band gap compared to nitrogen-free GaInAs is observed. Photoluminescence results are used to determine the interband transition energies. The results are compared with the theoretical values obtained using the band-anticrossing model. When the device is illuminated with monochromatic light, a finite photovoltage develops in the plane of the quantum wells due to Fermi level fluctuations.
Low-Threshold 1.3-um GaInNAs Quantum-Well Lasers Using Quaternary-Barrier Structures
C. Y. Jin, H. Y. Liu, S. Y. Zhang, and M. Hopkinson, 2008
GaInNAs quaternary-barrier structures, where indium is incorporated to achieve the lattice-matched condition, have been employed for 1.3-um GaInNAs–GaAs single- (SQW) and triple-quantum-well (TQW) lasers. Compared to a GaNAs ternary-barrier structure, photoluminescence results from the quaternary-barrier sample show improved optical properties. Threshold current densities have been achieved with the lowest values of 150 and 529 A/cmP for GaInNAs SQW and TQW lasers at room temperature, respectively.
Japanese Journal of Applied Physics, 2004
A quality improvement of the III-V dilute nitride semiconductor alloy, GaInNAs, grown by metalorganic chemical vapor deposition (MOCVD) on a GaAs substrate is reported for 1.3 mm-wavelength lasers. GaInNAs wafers were grown at various growth temperatures, V/III ratios, and growth rates. The photoluminescence (PL) efficiency of GaInNAs/GaAs quantum wells (QWs) was increased by lowering the growth temperature and increasing the V/III ratio in the growth conditions conventionally used for nitrogen (N)-free GaInAs/GaAs QW growth. These conditions are important for realizing high PL efficiency because they prevent the inhomogeneity of the immiscible alloy of GaInNAs. It was also observed that the optimal window for the growth temperature, V/III ratio, and growth rate for the GaInNAs is narrower than that of N-free GaInAs QWs. After careful optimization of the growth conditions, GaInNAs/GaAs QW lasers with various emission wavelengths were fabricated. Low-threshold current densities of 0.17 kA/cm 2 /well, 0.18 kA/cm 2 /well, and 0.44 kA/cm 2 /well are obtained for emission wavelengths of 1.25 mm, 1.30 mm, and 1.34 mm, respectively. The results obtained for growth conditions and lasing characteristics are useful in further improving 1.3 mm or longer wavelength GaInNAs lasers grown by MOCVD.
Journal of Luminescence, 2013
The effect of indium and nitrogen mole concentrations on the nonlinear optical properties in a Ga 1Àx In x N y As 1Ày =GaAs single quantum well under the intense laser field is theoretically studied within the effective mass approximation and the envelope function approach. The analytical expressions of optical properties are obtained by using the compact density-matrix approach. The numerical results show that the linear, third-order nonlinear and total absorption and refractive index changes depend both on the intense laser field and on the indium and nitrogen concentrations. From the findings of this study, it has been concluded that the linear and nonlinear optical properties in a Ga 1Àx In x N y As 1Ày =GaAs single quantum well under the intense laser field can be tuned by changing the indium and nitrogen mole fraction.
Theoretical and experimental analysis of 1.3-μm InGaAsN/GaAs lasers
IEEE Journal of Selected Topics in Quantum Electronics, 2003
We present a comprehensive theoretical and experimental analysis of 1.3-m InGaAsN/GaAs lasers. After introducing the 10-band k p Hamiltonian which predicts transition energies observed experimentally, we employ it to investigate laser properties of ideal and real InGaAsN/GaAs laser devices. Our calculations show that the addition of N reduces the peak gain and differential gain at fixed carrier density, although the gain saturation value and the peak gain as a function of radiative current density are largely unchanged due to the incorporation of N. The gain characteristics are optimized by including the minimum amount of nitrogen necessary to prevent strain relaxation at the given well thickness. The measured spontaneous emission and gain characteristics of real devices are well described by the theoretical model. Our analysis shows that the threshold current is dominated by nonradiative, defect-related recombination. Elimination of these losses would enable laser characteristics comparable with the best InGaAsP/InP-based lasers with the added advantages provided by the GaAs system that are important for vertical integration.