22. Juni 2020 / ingzhong Yang, Cornelius Nawrath, Robert Keil, Raphael Joos, Xi Zhang, Bianca Höfer, Yan Chen, Michael Zopf, Michael Jetter, Simone Luca Portalupi, Fei Ding, Peter Michler, and Oliver G. Schmidt

Quantum dot-based broadband optical antenna for efficient extraction of single photons in the telecom O-band

Long-distance fiber-based quantum communication relies on efficient non-classical light sources operating at telecommunication wavelengths. Semiconductor quantum dots are promising candidates for on-demand generation of single photons and entangled photon pairs for such applications. However, their brightness is strongly limited due to total internal reflection at the semiconductor/vacuum interface. Here we overcome this limitation using a dielectric antenna structure. The non-classical light source consists of a gallium phosphide solid immersion lens in combination with a quantum dot nanomembrane emitting single photons in the telecom O-band. With this device, the photon extraction is strongly increased in a broad spectral range. A brightness of 17% (numerical aperture of 0.6) is obtained experimentally, with a single photon purity of ��(2)(0)=0.049±0.02 at saturation power. This brings the practical implementation of quantum communication networks one step closer.

Publication: Quantum dot-based broadband optical antenna for efficient extraction of single photons in the telecom O-band
externer Link Optics Express

Contact person: C. Nawrath

 

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