量子点-等离激元复合型光子逻辑器件原理与实现

Plasmonic logic devices could be widely applied in optical computing, ultrafast information processing. However, the propagation loss in plasmonic devices is quite high, which has limited the extinction coefficient and the integration of the plasmonic logic devices. In this research, based on the logic gates in plasmonic slot waveguides the applicant has realized, a new model of plasmonic logic gates is established in quantum dot-plasmonic composite waveguides, in which the florescence of quantum dots will provide loss compensation in the plasmonic waveguides. The energy and charges transfer between the quantum dots and plasmonic waveguide will be deeply studied, in order to increase the compensation efficiency. Based on these composite plasmonic waveguides, various plasmonic logic gates will be realized, such as XOR gates, XNOR gates, with more steady signal and higher extinction coefficient. The influence of optical characteristics of the quantum dots to the signal of the logic gates will be also studied. Two and even more plasmonic logic gates will be cascaded to achieve more complex logic devices, such as half-adder, parity checker. This research is helpful to deeply understand the interaction between quantum dots and plasmonics, will improve the optical performance of the plasmonic photonic devices, and encourage the integration of nanophotonic devices and its application in optical calculation and optical interconnection networks.

表面等离激元光子逻辑器件在光计算、超高速信息处理等领域具有重要应用，但等离激元模式较强的传输损耗限制了逻辑器件信号对比度和器件集成化。针对这一问题，本项目在申请人此前对等离激元槽波导逻辑门的研究基础上，建立量子点-等离激元复合型光子逻辑器件模型，利用量子点荧光实现对表面等离激元逻辑器件中能量损耗的补偿；深入研究量子点与等离激元波导间的能量、电荷转移机理，进而提高量子点荧光对等离激元波导损耗的补偿效率；在此基础上实现表面等离激元全光异或门、同或门等多种光子逻辑门，提高逻辑门的信号对比度和稳定性，并研究量子点光学特性对逻辑信号的影响；进一步将两个乃至多个等离激元全光逻辑门级联，实现半加器、偶校验器等具有更复杂逻辑功能的光子逻辑器件。本项目的研究有利于深入了解量子点与等离激元相互作用的机制，提高等离激元纳米光子器件的光学性能，促进纳米光子学器件的集成化及其在光信息处理、光互联网络中的应用。

针对离激元模式较强的传输损耗对逻辑器件信号对比度和器件集成化的限制，提出了量子点-等离激元复合型光子逻辑器件模型，通过聚焦离子束刻蚀结合电子束曝光模板填充和套刻技术，制备了量子点-等离激元逻辑器件，利用量子点荧光实现对等离激元逻辑器件中能量损耗的补偿，实现了高信号对比度的复合结构全光逻辑门，研究有利于提高等离激元纳米光子器件的光学性能，促进纳米光子学器件的集成化及其在光信息处理、光互联网络中的应用。项目同时研究了杂化等离激元模式的超快动力学弛豫过程，讨论了杂化等离激元结构几何间隔对弛豫动力学过程的影响，对实现超快响应的全光逻辑运算具有指导意义。