基于新型光学腔的集成电泵浦纳米激光器的研究

While a fundamental element in photonic integration, the development of nanoscale light sources poses many challenges. As typical optical resonators require a volume larger than the sub-wavelength continued reduction of the footprint of nanolasers is difficult, which hampers its application in photonic integration, optical storage and optical sensing. In addition, fabrication problems due to lattice-mismatched material systems is an issue for hybrid integration of relatively high-cost lasers and passive optical devices. Furthermore, due to the high loss of nanocavities, typical nanolasers exhibit an intrinsic high threshold, let alone at electrically-driven operation. With the aim at solving these above problems this project will, from a theoretical perspective, focus on the fundamentals of nanolasers, novel nanocavity structures and layer structures for integrated lasers, targeting electrically-driven operation realized in small volumes and at low thresholds. Output performance and fabrication technology of such novel nanolasers targeting a reliable on-chip photonic integration will furthermore be investigated. Finally, tuning mechanism and a new method for efficient laser tuning based on subwavelength structures will be developed. We believe the proposed work on such flexible integrated nanolasers will greatly contribute to the new flexibility of laser physics and the development of novel nanolasers.

作为光集成器件中最关键的一部分，新型纳米光源被认为是当今纳米光子学领域极具挑战性的课题。由于采用传统光学反馈谐振腔的激光器无法超越半波长谐振腔极限，纳米激光器尺度无法继续缩小，这对于光集成、存储及传感等领域都是不利的。此外，要将价格较高昂的激光器与低成本的无源器件集成在一起，由于两者的波导材料不同，其加工工艺和集成的难度非常大。而且纳米光学腔的损耗大，纳米激光器的阈值一般较高，难以实现电驱动工作方式，不利于集成应用。针对这三大技术难点，本项目将从基础理论上研究纳米激光器机制，研究面向集成应用的新型纳米腔和有源层状结构，得到超小体积，低阈值工作效果同时，实现电驱动工作模式。另外我们研究纳米激光器输出特性和特异集成工艺，目标解决片上集成的关键技术问题。最后我们将研究纳米激光器的调谐能力，探索多种有效的调谐方式，实现更灵活的片上纳米激光器，为该领域带来新的研究维度，推动新型纳米激光器的发展。

作为光集成器件中最关键的一部分，新型纳米结构光源被认为是当今纳米光子学领域极具挑战性的课题。本项目研究了溶液法制备可用于深紫外光源的尺寸可调的铝纳米颗粒的制备技术，首次实现了短波铝量子点的高量子产率发光；研究了研究低损耗强约束的纳米波导。研究了量子点与纳米谐振腔的耦合，实现了量子点和谐振腔的耦合状态可以被激发的偏振光调节。研究局部光场干涉对局域在纳米尺度光场的空间，频域，和时域的有效调节作用；研究了基于人工超材料、易工业量产的谐振腔与在单光子发射领域的应用。本项目首次实现短波（350 – 400 nm）可调铝量子点的制备，完成了一种新型低损耗并且强约束的纳米光波导的设计，品质因子达到了6.5×106，用于实现小尺寸和低阈值的纳米激光器。实现了一种增强单光子发射几率的激光谐振腔，Purcell Factor达到了3.3 ×104。完成了将单量子点和纳米谐振腔的耦合，通过调节量子点实现了局部场强50倍的变化。完成了采用人工超材料实现的开放谐振腔的品质因子比平板谐振腔高出了15倍。该研究为用于制作高效，超小的纳米激光器，开拓了新局面。