液相飞秒激光烧蚀法制备石墨烯复合材料及其非线性光学性质

Graphene is an ultra-broadband saturable absorber, which is a matter of great concern and can work as an optical switch for controlling generation of ultra-short pulse laser. However, the relatively low optical absorption strength and optical modulation depth hinder its wide application. Designing and fabricating hybrids with graphene and strong nonlinear optical nanomaterials, to utilize the nonlinear optical response of the nanomaterials, the high electron transportation rate of graphene and the strong coupling between two components, is an important way to obtain high-performance nonlinear optical graphene hybrids. In this project, we will use femtosecond laser ablation in liquid to prepare in situ graphene hybrids with new nonlinear optical nanomaterials, such as ultra-small plasmonic semiconductor nanocrystals, which will enhance the nonlinear optical response of graphene in the near-infrared to mid-infrared region. We will control the size, loading density and doping concentration of the nanocrystals to modulate the optical properties of graphene hybrids. The ultra-fast optical spectroscopy will be adopted to uncover the charge transfer characteristic between nanocrystals and graphene. Using graphene hybrids with saturable absorption behavior as an optical switch, near-infrared and mid-infrared ultra-short pulse laser will be generated with high-power and high-efficiency. This project will provide a new ultra-fast optical switch for the generation of high performance pulsed laser and will also expand the application of pulsed laser ablation in liquid in the preparation of nanomaterials.

石墨烯是一种备受关注的超宽带饱和吸收体，可作为控制超短脉冲激光输出的光开关材料，但较低的光吸收强度和光学调制深度限制了其广泛应用。设计并制备强非线性光学纳米材料与石墨烯的复合结构，以利用纳米材料的非线性光响应、石墨烯的高电子传输速率以及两者之间的强烈耦合作用，是获得高性能非线性光学石墨烯复合材料的重要途径。本项目拟采用液相飞秒激光烧蚀法制备等离子体半导体超细纳米晶等新型非线性光学纳米材料与石墨烯的原位复合结构，增强石墨烯在近红外到中红外的非线性光响应。通过控制纳米晶的尺寸、负载密度、掺杂浓度等来调控石墨烯复合材料的光学性质，并借助超快光谱等手段揭示纳米晶与石墨烯之间的载流子输运特性。利用具有饱和吸收功能的石墨烯复合材料作为光开关，实现高功率高效率近红外和中红外超短脉冲激光输出。本项目的成果将为高性能脉冲激光的制造提供新的超快光开关材料，并拓展液相脉冲激光烧蚀法在纳米材料制备领域的应用范围。

激光诱导光学功能纳米材料的制备与调控受到了非常多的关注。本项目主要研究内容和成果如下：.1. 开发了通用的光诱导法制备一系列掺杂氧化物、硫化物、氮化物、碳化物等等离子体半导体纳米晶，实现了对纳米晶缺陷结构的超快精密操控，研究了其在800-2500nm波段的光响应，并将其与PVA混合，构筑了薄膜，用于超快激光锁模，实现了超快激光输出。.2. 发现了超快激光诱导调控玻璃内部微区离子分布新规律，解决了在微纳尺度对玻璃化学组成和结构调控的难题，提出了对玻璃三维微区发光宽波段连续调控的路线，获得发光波长在480到700 nm宽波段连续可调的半导体纳米晶点阵。这项研究不仅在功能玻璃领域，而且在整个发光材料领域，首次实现在单一发光材料内部构建光致发光从蓝色到红色宽波段连续可调的微纳结构，具有重要材料研究理论意义与应用价值。.3. 建立了超快激光在玻璃内部诱导形成三维超分辨周期光场的理论和实验模型，构筑了三维超分辨光子织构；提出了晶核效应促进超快激光诱导纳米晶形成机制，解决了超分辨结构大面积制造难题。.4. 提出利用纳米晶阵列构筑micro-LED器件这一全新方案。利用蓝光micro-LED芯片作为激发光源，构筑了micro-LED器件。利用空间全息光场作为激发源，开发了玻璃全息显示以及三维立体显示器件。开发了超快激光单脉冲调控玻璃局部拓扑结构、金属团簇化以及离子价态等，大大提高了光存储信息写入效率，其寿命可达一千万年以上，实现了基于发光调控的迄今为止最长数据存储寿命。开发了超低损耗三维光波导，解决了优化超快激光直写的光波导性能的一系列难题，耦合损耗、传输损耗、弯曲损耗等性能指标处于世界领先水平，与华为合作，构筑了具有实用价值的光互连器件，在光量子芯片、光计算芯片以及拓扑物理研究方面将有广泛的应用前景。.负责人以第一/通讯作者在Science、Light：Science & Applications、Laser & Photonics Reviews、Chemistry of Materials等高影响力期刊发表18篇，申请发明专利7项，在国内外重要学术会议作邀请报告22次，培养3名博士生、2名硕士生。