The molecular beam epitaxial growth and characteristics of 1.45μm metamorphic InAs quantum dot tunnel injection lasers on GaAs have been studied. Under optimized growth conditions, the quantum dots exhibit photoluminescence linewidths ∼30meV and high intensity at room temperature. The lasers are characterized by ultralow threshold current (63A∕cm2), large frequency response (f−3dB=8GHz), and near-zero α parameter and chirp.

https://deepblue.lib.umich.edu/bitstream/handle/2027.42/87801/153109_1.pdf;sequence=2

Growth and characteristics of ultralow threshold 1.45 μm metamorphic InAs tunnel injection quantum dot lasers on GaAs

In the past few years, GaInNAsSb has been found to be a potentially superior material to both GaInNAs and InGaAsP for communications wavelength laser applications. It has been observed that due to the surfactant role of antimony during epitaxy, higher quality material can be grown over the entire 1.2 – 1.6 µm range on GaAs substrates. In addition, it has been discovered that antimony in GaInNAsSb also works as a constituent that significantly modifies the valence band. These findings motivated a systematic study of GaInNAsSb alloys with widely varying compositions. Our recent progress in growth and materials development of GaInNAsSb alloys and our fabrication of 1.5 – 1.6 µm lasers are discussed in this paper. We review our recent studies of the conduction band offset in (Ga,In) (N,As,Sb)/GaAs quantum wells and discuss the growth challenges of GaInNAsSb alloys. Finally, we report record setting long wavelength edge emitting lasers and the first monolithic VCSELs operating at 1.5 µm based on GaInNAsSb QWs grown on GaAs. Successful development of GaInNAsSb alloys for lasers has led to a much broader range of potential applications for this material including: solar cells, electroabsorption modulators, saturable absorbers and far infrared optoelectronic devices and these are also briefly discussed in this paper.

Development of GaInNAsSb alloys : Growth, band structure, optical properties and applications

We demonstrate the 1.58 mu m emission at room temperature from a metamorphic In0.6Ga0.4As quantum well laser grown on GaAs by molecular beam epitaxy. The large lattice mismatch was accommodated through growth of a linearly graded buffer layer to create a high quality virtual In0.32Ga0.68As substrate. Careful growth optimization ensured good optical and structural qualities. For a 1250x50 mu m(2) broad area laser, a minimum threshold current density of 490 A/cm(2) was achieved under pulsed operation. This result indicates that metamorphic InGaAs quantum wells can be an alternative approach for 1.55 mu m GaAs-based lasers. (C) 2007 American Institute of Physics.

1.58 mu m InGaAs quantum well laser on GaAs

Molecular beam epitaxy growth of 1.55 μm GaInNAs(Sb) double quantum wells with bright and narrow photoluminescence

We report molecular beam epitaxial growth and characterization of dilute nitride InAsN:Sb. X-ray diffraction, energy dispersive x-ray spectrometry, and electron probe microanalysis revealed that nitrogen incorporation is significantly enhanced by introduction of Sb flux during growth, together with a dramatic improvement of the photoluminescence. These observations were attributed to the surfactant effect of Sb which suppresses the surface diffusion length of nitrogen and improves the homogeneity of the alloy. Sb incorporation is enhanced with the presence of nitrogen which was associated with the surface kinetic of growth. InAsN:Sb∕InAs p-i-n light emitting diodes operating near 4.0μm were also realized.

Molecular beam epitaxial growth of InAsN:Sb for midinfrared Optoelectronics

Starting from the growth of high-quality 1.3μmGaInNAs∕GaAs quantum well (QW), the QW emission wavelength has been extended up to 1.55μm by a combination of lowering growth rate, using GaNAs barriers and incorporating some amount of Sb. The photoluminescence properties of 1.5μm range GaInNAsSb∕GaNAs QWs are quite comparable to the 1.3μm QWs, revealing positive effect of Sb on improving the optical quality of the QWs. A 1.59μm lasing of a GaInNAsSb∕GaNAs single-QW laser diode is obtained under continuous current injection at room temperature. The threshold current density is 2.6kA∕cm2 with as-cleaved facet mirrors.

H. Q. Ni

Papers

GaAs-based room-temperature continuous-wave 1.59 {mu}m GaInNAsSb single-quantum-well laser diode grown by molecular-beam epitaxy