Single-photon emission in the telecom C-band in a micropillar cavity with an InAs/InGaAs quantum dot

We present the design and experimental demonstration of a micropillar metamorphic cavity structure with an embedded InAs/InGaAs quantum dot, intended for single-photon generation in the telecommunication C-band. The microcavity, incorporating a single GaAs/AlGaAs distributed Bragg reflector, is designed to provide a photon extraction efficiency of $15\%$ into a numerical aperture of $0.7$. The structure, fabricated by molecular beam epitaxy, photolithography, and plasma-enhanced chemical etching, exhibited an average C-band photon emission rate of $ \sim 1$ MHz at the first lens with a second-order correlation function of $g^{(2)}(0)= 0.14$.