Dresden 2017 – scientific programme

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HL: Fachverband Halbleiterphysik

HL 58: Quantum Dots: Optical Properties IV

HL 58.3: Talk

Wednesday, March 22, 2017, 15:30–15:45, POT 151

InGaAs quantum dots as light source for silicon photonics — •Norbert Witz, Matthias Paul, Jan Kettler, Michael Jetter, Simone L. Portalupi, and Peter Michler — IHFG, IQST Center and SCoPE, University of Stuttgart

One of the greatest needs of silicon photonics is an efficient light source, since many other functionalities have been already demonstrated and optimized. Indeed, being an indirect bandgap material, the photon emission in silicon is a three particle process thereby resulting in low efficient light emission. An attractive alternative is found in III/V semiconductor materials, which exhibit excellent optical properties. Especially semiconductor quantum dots (QDs) are promising candidates for this task. Adjusting the growth conditions, it is possible to tailor QD size and shape so that the emission wavelength shifts into the telecom O- or C-band at 1.3µm or 1.55µm. Because of the large lattice mismatch, monolithical growth of III/V materials on silicon substrate causes the formation of defects, which could prevent the efficient photon emission from the QDs. To evade this problem, III/V light sources grown by metal-organic vapour-phase epitaxy (MOVPE) have been directly glued onto a silicon chip. The emitted light is coupled into a single-mode waveguide by a diffractive Bragg grating, optimized for the spectral range of the glued sample. In order to fabricate a compact device, it is inevitable to excite the light source electrically. For this reason electrically pumped samples, with InGaAs QDs serving as an active medium have been developed.