1.3 μm GaAs-based laser using quantum dots obtained by activated spinodal decomposition
ABSTRACT Low threshold current density (Jth=65 A/cm2) operation near 1.3 μm at room temperature (RT) is realised for lasers using InAs-InGaAs-GaAs quantum dots (QDs). The lasing occurs via the QD ground state for cavity length L>1 mm. The differential efficiency is 40% and internal losses are 1.5 cm. The characteristic temperature near RT is 160 K.
Article: Low-threshold current density 1.3-μm InAs quantum-dot lasers with the dots-in-a-well (DWELL) structure[show abstract] [hide abstract]
ABSTRACT: The wavelength of InAs quantum dots in an In/sub 0.15/Ga/sub 0.85/As quantum-well (DWELL) lasers grown on a GaAs substrate has been extended to 1.3-/spl mu/m. The quantum dot lasing wavelength is sensitive to growth conditions and sample thermal history resulting in blue shifts as much as 73 nm. The room temperature threshold current density is 42.6 A cm/sup -2/ for 7.8-mm cavity length cleaved facet lasers under pulsed operation.IEEE Photonics Technology Letters 07/2000; · 2.19 Impact Factor
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ABSTRACT: The ultrafast gain and index dynamics in a set of InAs-InGaAs-GaAs quantum-dot (QD) amplifiers are measured at room temperature with femtosecond resolution. The role of spectral hole-burning (SHB) and carrier heating (CH) in the recovery of gain compression is investigated in detail. An ultrafast recovery of the spectral hole within ~100 fs is measured, comparable to bulk and quantum-well amplifiers, which is contradicting a carrier relaxation bottleneck in electrically pumped QD devices. The CH dynamics in the QD is quantitatively compared with results on an InGaAsP bulk amplifier. Reduced CH for both gain and refractive index dynamics of the QD devices is found, which is a promising prerequisite for high-speed applications. This reduction is attributed to reduced free-carrier absorption-induced heating caused by the small carrier density necessary to provide amplification in these low-dimensional systemsIEEE Journal of Selected Topics in Quantum Electronics 06/2000; · 3.78 Impact Factor