High-β lasing in photonic-defect semiconductor-dielectric hybrid microresonators with embedded InGaAs quantum dots

• Published in: Applied physics letters 2024-01, Vol.124 (4)
• Main Authors: Gaur, Kartik, Shih, Ching-Wen, Limame, Imad, Koulas-Simos, Aris, Heermeier, Niels, Palekar, Chirag C., Tripathi, Sarthak, Rodt, Sven, Reitzenstein, Stephan
• Format: Article
• Language: English
• Subjects: Bragg reflectors; Defects; Dielectrics; Emission; Group III-V semiconductors; High temperature; Holes; Lasing; Microlasers; Photonics; Quantum dots; Red shift
• ISSN: 0003-6951; 1077-3118
• DOI: 10.1063/5.0177393

We report an easy-to-fabricate microcavity design to produce optically pumped high-β quantum dot microlasers. Our cavity concept is based on a buried photonic-defect for tight lateral mode confinement in a quasi-planar microcavity system, which includes an upper dielectric distributed Bragg reflector (DBR) as a promising alternative to conventional III–V semiconductor DBRs. The cavities show distinct emission features with a characteristic photonic-defect size-dependent mode separation and Q-factors up to 17 000. Comprehensive investigations further reveal lasing operation with a systematic increase (decrease) of the β-factor (threshold pump power) with the number of mirror pairs in the upper dielectric DBR. Notably, due to the quasi-planar device geometry, the microlasers show high temperature stability, evidenced by the absence of temperature-induced redshift of emission energy and linewidth broadening typically observed for nano- and microlasers at high excitation powers. The device exhibits remarkable lasing performance, maintaining efficacy even under elevated temperatures of up to 260 K.