On-chip Integrable Spectrally Uniform Ordered Quantum Dot Single Photon Source Array with High Emission Purity (>98.99%) for Scalable Quantum Optical Networks

Towards the goal of building scalable on-chip optical networks we have proposed a new paradigm that integrates an array of mesa top single quantum dot (MTSQD) single photon sources (SPSs) with dielectric light manipulating units (LMUs) [1]. We demonstrated InGaAs/GaAs MTSQDs in 5x8 array [1] showing remarkably improved spectral uniformity than the typically studied self-assembled island QDs but, more importantly, several pairs of MTSQDs exhibit emission wavelengths within 300μeV, the instrument resolution [2]. The measured single photon emission purity was thus limited to 90% at 9K. In this talk we report studies with improved high resolution of ~10μeV demonstrating single photon emission purity > 98.99% (g⁽²⁾(0)<0.02) in these MTSQDs at 9.4K. The MTSQD neutral exciton’s intrinsic linewidth and fine structure splitting are found to be ~10µeV and <10µeV, respectively. The results highlight the potential of the spatially-ordered MTSQDs-LMU integrated system for realizing quantum optical circuits[3]. Work on examining photon indistinguishability and coherence is underway.
[1] Jiefei Zhang et.al, J. Appl. Phys. 120, 243103 (2016)
[2] Jiefei Zhang et.al, APS March (2017)
[3] S. Chattaraj, arXiv:1712.09700v2(2018)