新型多光子吸收诱导蓝光发射材料特性研究

In the past decades, multi-photon absorption (MPA) processes has gain enormous interest from the points of view of both fundamental physics and technological application. This momentum is essentially prompted by a number of potential applications of multi-photon absorption molecules including frequency upconversion lasing, optical limiting, three-dimensional (3D) fluorescence microscopy and imaging, 3D micro-fabrication and optical data storage. Recently, a large number of molecules with large multi-photon absorption (MPA) cross sections have been reported. However, the emitting wavelengths of the most of these molecules locate in the region of 500-700 nm. The study of multi-photon fluorescence molecules with efficient blue emission is still lacking, which blocks the development of multi-channel MPA induced fluorescence microscopy because efficient blue emission molecules are necessary for tagging some specific cellular components. This project will perform the studies on the multi-photon absorption properties of several groups of novel organic compounds. Various physical phenomena such as two-photon absorb induced fluorescence, multi-photon absorption induced up-converted lasing and the interaction and inter-control of high order processes in nonlinear material will be researched experimentally and theoretically in this project. The structure and property relationship of the multi-photon absorption molecules including the effects of the terminal donor group, accepter group and π-conjugated system will be studied by analyzing the experiment data and performing the numerical simulation. This project will be helpful for providing the guide to design efficient multi-photon-induced violet-blue emitting molecules. Our works will open a new avenue to develop highly effective multi-photon absorbing fluorophores for various potential applications.

近年来，多光子吸收效应的研究成为令人关注的热点，多光子吸收效应在频率上转换激射、光学限幅、双光子荧光显微和成像、三维光信息存储、光学微加工以及光生物学等许多领域展示出良好的应用前景。具有强多光子吸收特性的蓝光发射材料目前还比较缺乏,但蓝光材料在多光子吸收的应用领域中又是必不可少的重要部分。本项目的主体工作将利用超快光谱和理论计算相结合的方法去研究分子结构与光学性能关系, 为合成具有大多光子吸收截面的蓝光发射材料提供依据。另一方面，我们将以新型蓝光发射有机化合物为研究对象，从理论和实验两方面对新有机化合物的多光子吸收特性、多光子诱导荧光特性、上转换激射和多光子吸收与自聚焦、受激拉曼相互作用进行深入的研究，以探索出多光子诱导蓝光激射的形成机理。为获得高效率的上转换激射提供理论依据。通过以上研究,将为研制和开发新型优质的蓝光发射多光子吸收材料提供指导,推动多光子吸收材料进一步走向应用.

本项目研究了金纳米棒的荧光上转换特性以及其在细胞显微成像中的应用。我们发现金纳米棒具有良好的上转换发光特性，并且对多种细胞的毒性都很低。这样即得到良好的上转换荧光显微图像，又不会对生物体有很大的伤害。另一方面，我们的研究发现金纳米棒在在红外光照射下，其表面等离子共振波会产生相互耦合而使光场的能量场得到局部增强，从而产生极大的热量可在很短时间内杀死癌细胞。而当我们在合成金纳米棒过程中掺入少量铜原子以改变金纳米棒的力学性能，使其在超声作用下变成量子点，便可诱导癌细胞。我们还研究了一系列掺杂稀土元素硼酸盐玻璃的上转换发光特性。经过实验我们发现，这些掺杂稀土元素Tb3+, Eu3+, 和 Dy3+的玻璃被波长长达2.6um的红外光照射依然有较好的上转换发光现象。而这一系列的玻璃制作温度高达1200度，具有良好的可塑性与耐高温性能。研究了一系列以稀土离子Eu3+为发光中心的硼酸盐玻璃上转换发光性能，研究了其耐热性，化学稳定性和力学稳定性，通过调节加入硼酸盐基底的NaYF4与Bi3+离子成分来抑制原基底晶格中的声子模式，提高上转换发光效率。