Ultrabright sources of single and entangled photon pairs

该项目的目的是制造近红外光谱范围内不可分辨的单光子和纠缠光子的光泵浦超亮源以及红色光谱范围内的光泵浦和电泵浦单光子源。第一个目标将最终实现一个新设计的腔结构，包括定位量子点（QD），波导耦合和共振激发技术的组合。因此，嵌入高反射DBR结构中的InAs/GaAs量子点将以纳米精度精确地放置到微柱中。然后，锥形一维纳米线将连接到这些支柱，以实现具有高激光杂散光抑制的共振侧激发。利用这个方案，我们期望建立一个非常明亮的纠缠光子源，具有高保真度和低失相。第二个目标是用GaInP/AlGaInP材料系统实现可见红光范围的超亮电驱动单光子源。在这里，量子点，这次是InP QD，将被嵌入到高反射DBR中，其现在被掺杂以允许电接触。然后，将形成具有上述精确精度的用于谐振腔LED（RC-LED）的柱结构或台面。RC-LED还将接收一个狭窄的氧化物孔径，以确保低电流仅通过器件中间的单个QD。在完成两种类型的结构后，将可获得具有高GHz重复率、高收集效率和低背景的电驱动源。这些具有挑战性的目标只能通过目前在制造和表征这类光子源方面的世界领先团体的合作来实现。特殊的关键资格是Pascale Senellarts小组开发的原位光刻工艺和斯图加特Peter Michlers小组开创的用于共振激子和双激子制备的侧激发技术。

The aim of this project is the fabrication of optically pumped ultrabright sources of indistinguishable single and entangled photons in the near infrared spectral range and optically and electrically pumped single photon sources in the red spectral range. The first goal will be ultimately achieved by the combination of a newly designed cavity structure including positioned quantum dots (QD), waveguide coupling and resonant excitation techniques. Therefore, InAs/GaAs quantum dots embedded in high reflective DBR structures will be precisely placed with nanometer accuracy into micropillars. Then tapered one-dimensional nanowires will be connected to these pillars to enable resonant side-excitation with a high laser stray-light suppression. With this schema, we expect to establish a very bright source of entangled photons with a high fidelity and low dephasing. The second goal will be the realization of an ultrabright electrically driven single photon source in the visible red spectral range with GaInP/AlGaInP material system. Here also quantum dots, this time InP QDs, will be embedded into high reflective DBRs, which are now doped to allow the electrical contacting. Then, either pillar structures or mesas for resonant cavity LEDs (RC-LEDs) with the above-mentioned precise accuracy will be formed. The RC-LEDs will additionally receive a narrow oxide aperture to ensure a low current flow only through the single QD in the middle of the device. After finalizing both types of structures, an electrically driven source with a high GHz repetition rate, high collection efficiency and low background will be available. These challenging goals can only be realized by the present cooperation of the world leading groups in the fabrication and characterization of these kind of photon sources. Special key qualifications are the in-situ lithography process developed in Pascale Senellarts group and the side-excitation technique for resonant exciton and biexciton preparation pioneered by Peter Michlers group in Stuttgart.