Rare-earth-doped and semiconductor nanocrystal lasers for photonic applications

该项目将开创由稀土掺杂的上转换纳米颗粒和/或发光半导体纳米晶体制成的微谐振器，以使新型微观/亚微观激光器能够用于光子集成电路，并作为传感和生物医学应用的增强型荧光/激光标记。背景资料：发光纳米粒子（尺寸为1 nm至50 nm）可以作为更高级别的微米级光子结构（超晶体或超组装体）的构建块，这些光子结构可以被设计用于增强荧光和光物质相互作用以及多功能性。我们的团队最近展示了使用半导体纳米晶体的微尺寸激光器，这些半导体纳米晶体在适当的条件下自组装成微球谐振器。这些结构是在非常小的尺度上研究激光现象的一个很好的平台。它们还为集成光学（作为微观光源）和生物医学科学（例如可用于体内的高效荧光和传感标签）的新应用创造了机会。我们现在正在将我们的“构建块库”扩展到稀土掺杂的上转换纳米颗粒-这些能够实现有效的反斯托克斯发射（例如，当被近红外光激发时，它们可以发射可见光或紫外光），这是在生物样品中使用微激光器的一个有吸引力的特征。我们的第一个目标是展示一种自组装的上转换激光器，这是迄今为止从未报道过的。因此，我们的团队正在开创这些新型微激光器，其基本目标是了解它们的物理特性，彻底改变病原体或污染物的靶向和检测方式，并建立创新的人工光学材料。该研究将有助于实现这些目标。据设想，重点将放在这些材料与光子集成电路的集成上（通过光刻和自组装，微激光集成和测试的光子元件的微制造），虽然有灵活性取决于学生的背景和愿望。目标：作为团队的一部分，学生将努力实现以下目标：（i）使用自下而上合成微激光器（自组装）和自上而下/自下而上混合制造方法; ㈡增加微型激光器的功能（能够与环境相互作用并“感知”环境）;（三）（材料和形态）和微型激光器的光学特性;进一步了解这些微结构中的物理过程;（iv）将微型激光器与光子电路组件集成-为新型集成光学和芯片实验室设备铺平道路;（v）启动和开发应用程序

The project will pioneer micro-resonators made from rare-earth doped upconverting nanoparticles and/or luminescent semiconductor nanocrystals in order to enable novel microscopic/sub-microscopic lasers for use in photonic integrated circuits and as enhanced fluorescent/lasing labels for sensing and biomedical applications. Background: Luminescent nanoparticles (1nm to 50nm in size) can act as the building blocks of higher level, micrometre-scale photonic structures (super-crystals or super-assemblies) that can be designed for enhanced fluorescence and light matter-interactions, as well as for multi-functionalities. Our team has recently demonstrated micro-size lasers using semiconductor nanocrystals that self-assemble into microsphere resonators under the right conditions. These structures are a great platform to study laser phenomena at a very small scale. They also create opportunities for new applications in integrated optics (as microscopic light sources) and in biomedical sciences (for example as efficient fluorescent and sensing labels that could be used in-vivo). We are now expanding our "building blocks library" to rare-earth doped upconverting nanoparticles - these enable efficient anti-Stokes emission (e.g., they can emit in the visible or UV when excited by near infra-red light), an attractive feature for utilisation of microlasers within biological samples. Our first target is to demonstrate a self-assembled upconverted laser, which has never been reported so far.Our team is therefore pioneering these new types of microlasers with the underlying goals of understanding their physics, of revolutionising the way pathogens or pollutants are targeted and detected, and of establishing innovative artificial optical materials. This studentship will contribute to achieving these goals. It is envisaged that the focus will be on integration of these materials with photonic integrated circuitry (microfabrication of photonic elements by lithography and self-assembly, microlaser integration, and testing), although there is flexibility depending on the student background and aspirations.Objectives: As part of the team the student will work towards the following objectives:(i) Synthesise microlasers using bottom-up (self-assembly) and hybrid top-down/bottom-up fabrication approaches;(ii) Add functionalities to the microlasers (to be able to interact with and "sense" their environment) through surface engineering;(iii) Characterise the physical (material and morphology) and optical properties of the microlasers; progress understanding of physical processes in these microstructures;(iv) Integrate microlasers with photonic circuitry components - paving the way for novel integrated optics and lab-on-chip devices;(v) Initiate and develop applications