Development of active surface plasmonic polariton waveguide

传统的光子或光电元件被设计成直接处理光波。为了充分放大或操纵光波，这些组件需要具有数千个波长（即在100微米到1毫米的范围内）的特征尺寸。因此，典型尺寸为几厘米的芯片不可能集成许多这样的组件。表面等离子体极化子（SPP）波，作为电磁场和自由电子在介电介质和导体界面上的共振，可以被紧密地限制在超过衍射极限的微小横截面积内，并且可以以比光波慢得多的速度传播，这意味着SPP波具有更短的等效波长，而SPP器件只需要大大缩小尺寸即可实现相同的功能。因此，我们可以构建密度大大增加的集成SPP器件，以实现传统集成光子或光电器件在光通信和光信号处理等领域不可能实现的复杂功能。由于SPP波与引导介质的相互作用时间大大延长，非线性效应大大增强，我们还可以期望孤立SPP器件的性能大大提高，甚至具有新的功能。然而，当前SPP波导的传播损耗是其应用的主要限制。本课题提出的有源SPP波导旨在同时实现对SPP波的引导、放大和控制。如果成功，它将克服SPP波勘探的主要障碍。因此，整个家族的器件及其集成可以开发范围从产生，放大，调制，传输和控制SPP波在光学频率。因此，它将对光通信网络、传感器系统和信号处理系统的先进组件的发展产生重大影响。通过本研究项目发明的结构和设备以及获得的知识也可能使该领域的其他研究人员和一些加拿大公司受益。

Conventional photonic or optoelectronic components are designed to deal with the optical wave directly. These components need a featured size in thousands of wavelength (i.e., in a range from 100micron to 1mm) in order to sufficiently amplify or manipulate the optical wave. Therefore, a chip in a typical size of several centimeters cannot have many such components integrated. The surface plasmonic polariton (SPP) wave, appearing as a resonance between the electromagnetic field and free electrons at a dielectric and conductor interface, can be tightly confined in a tiny cross-sectional area beyond the diffraction limit and can propagate at a much slower speed as compared to the optical wave, which means the SPP wave has a much shorter equivalent wavelength and the SPP device will only need a greatly reduced size for the same function. As such, we can build integrated SPP devices with greatly increased density to fulfill complex functions that will be impossible for conventional integrated photonic or optoelectronic devices in areas like optical communication and optical signal processing. We can also expect a greatly enhanced performance or even new functions on solitary SPP devices due to the largely extended interaction time of the SPP wave with its guiding medium and the greatly intensified nonlinear effect. The propagation loss in current SPP waveguides, however, sets a major limit to their applications. Our proposed active SPP waveguide in this research program is aimed to realize the guidance, amplification, and control of the SPP wave simultaneously. If successful, it will overcome the major obstacle in the exploration of the SPP wave. Consequently, a whole family of devices and their integrations can be developed ranging from the generation, amplification, modulation, transmission, and control of the SPP wave at the optical frequency. Hence it will have a significant impact on the development of advanced components for optical communication networks, sensor systems, and signal processing systems. The structure and device invented and knowledge acquired through this research program may also benefit other researchers in this field and a number of Canadian companies.