All-Fiber Quantum Optics with Colloidal Nanosemiconductors

光纤现在通常被称为传输光的互联网骨干，而纳米材料是定制物质特性以产生创新应用的工具;该提案是两种技术的会议，旨在实现直接在光纤内按需产生光子用于信息编码的长期目标。这种光纤网络发射和引导光量子，即光子，将是量子互联网从不可破解的密码学发展到保护在线机密信息的一步。在这种情况下，经济学家预测，到2030年，量子技术产业将达到82亿美元，雇用16，000名加拿大人。目前的单光子源都在光纤之外，面临着光耦合和便携性的挑战。此外，它们的架构和大多数制造方法不是那么简单和可扩展。这些问题将通过光纤中的发光二极管光源来解决，光纤可以很容易地拼接在一起。然而，半导体纳米晶体（即量子点）的胶体合成尚未提供可靠的量子技术系统。因此，我们将通过将量子点嵌入保护性透明塑料中进行加热并将其拉入光纤中来实现一石二鸟。实际上，光发射速率也将加速并与引入不可靠波动的其他机制的猝灭竞争。首先，我们将证明控制这种自发辐射率与不同的光纤设计感谢珀塞尔效应。为了验证该效果，将在光纤输出处记录嵌入的量子点集合的光致发光衰减迹线。量子点的浓度将是一个关键参数，在拉制光纤时将它们分离开来，然后将它们切割成单光子源，这将通过它们的反聚束统计来证实。其次，将在这些光源的端部添加类似镜子的界面，以增加光-物质耦合并进一步加速光发射。不同的策略来制造这些谐振光学腔，在激光器中发现，将在产生个人和不可区分的光子方面进行比较。然后，腔模或量子点能级将被调谐到彼此共振。在调谐过程中能级和模式的光谱反交叉将证实强耦合。第三，展望在单个光子上编码更多信息或在自旋状态上实现更鲁棒的编码，我们将探索在聚合物光纤中引入圆形量子环和纳米金刚石（包括氮空位中心）的新方法。最后，在短期内，具有成本效益的纤维合成和光纤制造促进了创新传感应用的发展：为当地技术转让和学生主导的创业创造了有利的环境。

Optical fibers are now commonly known as the Internet backbone transmitting light, whereas nanomaterials are a tool for customizing matter properties to generate innovative applications; this proposal is a meeting of both technologies towards the long term objective of generating photons on demand for information encoding, directly within optical fibers. A network of such fibers emitting and guiding light quanta, i.e. the photons, would be a step towards a quantum internet progressing from unbreakable cryptography to protect confidential information online. In this context, economists forecast an $8.2 billion quantum technology industry, employing 16 000 Canadians, by 2030. Current sources of single photons are all outside optical fibers, facing light coupling and portability challenges. Moreover, their architecture and most fabrication approaches are not so simple and scalable. These issues will be resolved with luminescent nanocrystal sources in optical fiber that can be easily spliced together. However, colloidal synthesis of semiconductor nanocrystals, namely quantum dots, has yet to deliver reliable quantum technological systems. Therefore, we will kill two birds with one stone by embedding the quantum dots in protective transparent plastic to be heated and drawn into an optical fiber. Indeed, the light emission rate will also accelerate and compete with the quenching of other mechanisms introducing unreliable fluctuations. Firstly, we will demonstrate control of this spontaneous emission rate with different optical fiber designs thanks to the Purcell effect. To verify the effect, photoluminescence decay traces of embedded quantum dot ensembles will be recorded at the fiber output. The concentration of quantum dots will be a key parameter to isolate them apart when drawing the optical fiber, then cutting them out into single photon sources as will be confirmed by their antibunching statistics. Secondly, mirror-like interfaces will be added at the ends of these sources to increase the light-matter coupling and accelerate the light emission even further. Different strategies to fabricate these resonating optical cavities, as found in lasers, will be compared in terms of generating individual and indistinguishable photons. Then, either the cavity modes or the quantum dot energy levels will be tuned into resonance with one another. A spectral anticrossing of levels and modes during tuning would then confirm a strong coupling. Thirdly, looking ahead towards encoding more information on a single photon or achieving more robust encoding on spin states, we will explore new methods to incorporate circular quantum rings and nanodiamonds, comprising nitrogen vacancy centers, in the polymer optical fibers. Finally in the shorter term, the cost-effective nanocrystal synthesis and fiber fabrication motivate the development of innovative sensing applications: an auspicious environment for local technology transfer and student-led entrepreneurship.