SKM 2023 – scientific programme

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HL: Fachverband Halbleiterphysik

HL 12: Semiconductor lasers I

HL 12.2: Talk

Monday, March 27, 2023, 15:15–15:30, POT 112

Cavity effects in hybrid resonators embedding InGaAs quantum dots — •Kartik Gaur, Sarthak Tripathi, Imad Limame, Ching-Wen Shih, Chirag Palekar, Sven Rodt, and Stephan Reitzenstein — Institut für Festkörperphysik, Technische Universität Berlin, Germany

InGaAs quantum dots (QDs) embedded in microcavities based on highly reflective distributed Bragg reflectors (DBRs) allow for the development of high Q-factor, low mode volume micropillar cavities which feature high light-matter interaction. This makes them almost ideal candidates for quantum light sources and high-β microlasers. However, epitaxially grown GaAs/AlAs DBRs suffer from relatively low refractive index contrast, and often high absorption of the optical pumping laser. Here, we propose replacing the upper III-V DBR with dielectric DBR based on λ/4-thick layers of SiO₂ and Si₃N₄ deposited using plasma-enhanced chemical vapor deposition. Numerical simulations are carried out to optimize the fabrication parameters and subsequently validate the optical properties. The MOCVD-grown InGaAs QD active region is integrated in the central one-λ GaAs cavity on top of the bottom DBR with 33 Al_0.2Ga_0.8As/Al_0.9Ga_0.1As mirror pairs, followed by electron beam lithography processing step to define photonic defects for lateral mode confinement. Such defects in the form of microlenses are created using a SiO₂ hard mask and wet chemical etching. We then deposit dielectric top DBR consisting of 15 λ/4-thick SiO₂ and Si₃N₄ mirror pairs. The final structure is investigated via low-temperature micro-photoluminescence.