Enhanced thermal stability of laser diodes with shape-engineered quantum dot medium

Vadim Tokranov, Michail M. Yakimov, A. Katsnelson, M. Lamberti, S. Oktyabrsky

Applied Physics Letters · 2003 · 38 citations · 13 references

Concepts

Abstract

Optical properties of the quantum dots (QDs) were optimized by shape engineering through the adjustment of the thickness of the GaAs overlayer prior to an additional heating step leading to QD truncation. QDs with a 6-nm-thick overlayer with the subsequent heating step were found to have the highest photoluminescence intensity at room temperature and the lowest luminescence bandwidth, 29 meV. 1.22 μm edge-emitting laser with a triple-layer truncated QD gain medium demonstrated room temperature threshold current density, 56 A/cm2, and saturated modal gain, 16 cm−1. An extremely high characteristic temperature for lasing threshold, T0=380 K up to 55 °C, and a maximum ground state lasing temperature of 219 °C were measured for these laser diodes.

References

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