Vertical-cavity surface-emitting lasers (VCSELs) have achieved remarkable performance in threshold, speed, and efficiency. However the VCSELs have so far achieved their performance without the benefit of a buried-heterostructure (BH) gain structure. A high quality BH gain structure can be expected to dramatically improve VCSEL performance by eliminating parasitic charging effects in the perimeter...
Laser diodes based on planar quantum wells produce power conversion efficiencies that tend to saturate at room temperature at ∼ 70%. These planar quantum well laser diodes have been heavily researched and developed and the power conversion efficiencies appear close to the material limits for optimized devices. The power conversion efficiency can be treated as a product of separate efficiencies based...
We show that the transparency current plays a central role in setting the temperature dependence of both undoped and p-doped quantum dot lasers. The influence of inhomogeneous broadening is also analyzed and shown to influence.
Low threshold QD laser with threshold current density <10 A/cm2 is experimentally shown and threshold current temperature dependence of a QD laser with an ideal delta function density of electronic states is analyzed.
A study of the threshold characteristics of quantum-dot (QD) laser diodes shows how inhomogeneous broadening and p-doping influence the QD laser's temperature dependence of threshold T0. The analysis includes the additional parameters of homogeneous broadening, quantum state populations, and threshold gain. The results show that while the source of negative T0 can occur due to different effects,...
Data are presented demonstrating that a low-threshold quantum dot laser diode can achieve very low internal optical loss. The broad-area laser diode operates at the wavelength 1.22 m and delivers 2 W of power from a 1.6 cm-long cavity with uncoated facets, with a lasing threshold current density of 10.4 A/cm2. The laser diode's internal waveguide loss is extracted from cavity length measurements to...
Large cavity, very low threshold single layer quantum dot laser diodes with threshold current density of 10 A/cm2, output power > 2 W, and very-low internal loss of 0.25 cm-1 are achieved at CW room-temperature. Mode-locked operation of a large cavity laser diode with 40 mum stripe width is demonstrated at 3.75 GHz repetition rate.
In this presentation, a continuous-wave room temperature lasing at a threshold current density of 11.7 A/cm2 is reported. This is the lowest threshold current density ever reported for continuous-wave room temperature operation of a laser diode, to the authors' knowledge.
The physics of quantum dot lasers are studied theoretically and experimentally to study their threshold temperature dependence, and the relationship between internal loss and threshold current density.
Data are presented showing that a quantum-dot laser diode can achieve a continuous-wave room-temperature threshold current density as low as 11.7 A/cm2. The broad-area laser diode operates at a wavelength of 1.22 mum and delivers a power level of 0.42 W with 40% maximum slope efficiency in p-up mounting without heatsinking. Spectral measurements indicate the onset of stimulated emission at ~6 A/cm...
Photonic crystal slab nanocavities containing one layer of quantum dots have exhibited: strong coupling to a single quantum dot; tuning by condensation of xenon gas; linewidth broadening due to ensemble dot absorption; gain and lasing.
Optical characterization of a novel type of semiconductor microcavity based on a fully-buried, all-epitaxial design reveals many properties essential for a manufacturable technology. We demonstrate detailed mode-imaging, lasing, as well as a sizeable Purcell effect.
Lasing behavior under optical pumping conditions is reported for photonic crystal double-heterostructure nanocavities with InAs quantum dot active regions. Coupling of this laser emission into a photonic crystal waveguide is also reported.
We have demonstrated high spontaneous emission coupling factor ~ 0.1 from photonic crystal nanolasers with quantum dots. This high coupling resulted from narrow homogenous broadening of the quantum dots and the small number of resonances
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