Design optimization for bright electrically-driven quantum dot single-photon sources emitting in telecom O-band
S. A. Blokhin, M. A. Bobrov, N. A. Maleev, Jan N. Donges, Leon Bremer, A. A. Blokhin, А. П. Васильев, A. G. Kuzmenkov, E. S. Kolodeznyi, V. A. Shchukin, N. N. Ledentsov, Stephan Reitzenstein, V. M. Ustinov
Abstract
A combination of advanced light engineering concepts enables a substantial improvement in photon extraction efficiency of micro-cavity-based single-photon sources in the telecom O-band at ∼1.3 µm. We employ a broadband bottom distributed Bragg reflector (DBR) and a top DBR formed in a dielectric micropillar with an additional circular Bragg grating in the lateral plane. This device design includes a doped layer in pin-configuration to allow for electric carrier injection. It provides broadband (∼8-10 nm) emission enhancement with an overall photon-extraction efficiency of ∼83% into the upper hemisphere and photon-extraction efficiency of ∼79% within numerical aperture NA=0.7. The efficiency of photon coupling to a single-mode fiber reaches 11% for SMF28 fiber (with NA=0.12), exceeds 22% for 980HP fiber (with NA=0.2) and reaches ∼40% for HNA fiber (with NA=0.42) as demonstrated by 3D finite-difference time-domain modeling.