Development of deterministic quantum-light sources from InP-based quantum dots in the telecom c-band

该项目的重点是从自组装的InP基单量子点（QD）中产生电信波长（1.55 μm）的非经典光，这些量子点被确定性地集成到光子微结构中，以增强光子耦合和发射控制。该项目解决了三个主要挑战：控制电子结构，提高光子提取效率，以研究光学产生的量子光态，即明亮的单光子和双光子（能量和偏振退化）和电驱动的单光子发射。我们将通过外延生长、外部调谐和使用原位电子束光刻确定性地将单个量子点集成到微透镜中来应对这些挑战。与较低的反射镜部分相结合的微透镜设计预计会导致光子提取效率的宽带增强，并将成为长波长非经典光的有效（量子）光学表征的基础。我们的目标是探索方便的外部控制的量子点微透镜的发射特性，主要是在双激子结合能的实现和系统的研究双光子发射的关键。在单光子发射方面，我们主要从电荷控制和载流子注入两个方面来研究不同激子复合物的性质。对于孪生光子，我们的目标是使用简并双激子-激子（XX-X）级联来产生时间相关光子对。为了系统地研究它们，我们将联合收割机的量子点微透镜与压电致动器，这允许方便的调谐和减少双激子结合能对精细结构分裂的明亮的X所需的双光子发射。我们的项目结合了相关团队在高质量电信波长InP基QD（UNIKASSEL）的生长和光学表征方面的领先专业知识，以及量子光源的确定性制造和半导体量子点（TUB）的量子光学研究。拟议研究的成果将大大推进电信波长量子光发射的知识状态，并将为基于光纤的量子通信和非线性光谱学的单光子和双光子源开辟令人兴奋的前景。

This project focuses on generation of non-classical light at telecom wavelengths (1.55 μm) from self-assembled InP-based single quantum dots (QDs), which are deterministically integrated into photonic microstructures for enhanced photon outcoupling and emission control. Project addresses three main challenges: control of the electronic structure, enhancement of photon extraction efficiency for study on optically-generated quantum light states, i.e. bright single- and twin-photons (degenerate in energy and polarization) and electrically-driven single-photon emission. We will tackle these challenges by epitaxial growth, external tuning and deterministically integrating single QDs into microlenses using in-situ electron-beam lithography. The microlens design in combination with a lower mirror section is expected to result in broadband enhancement of photon extraction efficiency and will be the basis for efficient (quantum)-optical characterization of non-classical light at long wavelengths. We aim at exploring convenient external control of emission properties of QD-microlenses mainly in terms of the biexciton binding energy crucial for realization and systematic study of twin-photons emission. Regarding single-photon emission, we focus on electrical charge control and electrical carrier injection to study properties of different excitonic complexes. With respect to twin-photons we aim at using the degenerate biexciton-exciton (XX-X) cascade to generate time-correlated photon pairs. In order to study them in a systematic way, we will combine the QD-microlenses with a piezo-actuator, which allows for convenient tuning and reduction of biexciton binding energy towards fine structure splitting of the bright X as required for twin-photon emission. Our project combines leading expertise of the involved groups on the growth and optical characterization of high-quality telecom-wavelength InP-based QDs (UNIKASSEL), and the deterministic fabrication of quantum light sources and quantum- optical study of semiconductor quantum dots (TUB). The output of the proposed research will significantly advance the state of knowledge on quantum light emission at telecom wavelengths and will open up exciting prospects for single- and twin-photon sources for fiber-based quantum communication and nonlinear spectroscopy.