Modeling and design of high density photonic integrated cricuits

光子集成电路（IC），首先由S。E.米勒在贝尔实验室于70年代初，有一个悠久的历史，但很少应用。实际上，大多数光学系统仍然是建立在由不同材料通过不同工艺制成的分立光子器件上。光子IC在密度和复杂性方面与电子对应物相比是苍白的，并且遭受折衷的性能和差的产量。光场在波导和谐振结构中的弱限制是光子集成电路中的一个基本问题，具有弱折射率对比/变化。因此，光与媒体之间的高密度集成和强相互作用变得极其困难。集成和交互对于实现针对不同应用的高级光信号处理功能是必不可少的。因此，限制和操纵芯片上的光场以及将光耦合到芯片中和从芯片耦合光的能力是实现鲁棒的、复杂的光子IC的关键使能因素。拟议的研究将调查和开发高密度光子器件和集成电路，以执行先进的光信号处理功能。这些高密度光子器件和IC与当前流行的光子晶体（PC）结构的不同之处在于，光场的限制、引导和谐振不是由于周期性折射率变化（即，"晶体效应“），但是对于强折射率对比（即，“缺陷效应”）。首先，该研究将致力于开发有效和准确的理论模型和数值技术，用于模拟光的矢量特性及其与介质的强相互作用。在这方面，大多数现有的模型和仿真技术是不够的，新的和改进的模型和算法需要提出和实施。其次，基本的波导和谐振结构将被检查的基础上考虑吸收和散射损耗，易于制造和表征等，通过使用大的折射率对比度的结构，我们将能够限制和操纵芯片上的光通过缩小几个数量级的光学器件的特征尺寸。几个强大的限制结构，例如，硅线、深刻蚀InP脊形波导、微环谐振器等，已经被提出并证明。研究的一个主要重点是研究和开发新的电路结构，以连接这些波导和谐振元件，形成复杂的光子集成电路。此外，我们将开发有效和准确的建模和仿真工具，用于研究PIC和片外元件之间的耦合。有效和强大的机制，耦合进和出的芯片将被检查。最后，我们将研究控制和操纵灯光的方法。将研究与所用材料有关的电、热和非线性效应。该研究将与集成光收发器，全光再生器等领域正在进行的研究密切相关，将寻求并加强与麦克马斯特研究人员以及外部工业和学术机构的密切合作，特别是在实验方面，以补充申请人的专业知识。这项研究如果成功，将揭示高密度光子IC的一些显著特征，并将最先进的PIC技术推向实际应用。几个博士生和PDF将在这一新兴技术中进行曝光和培训，并在建模，设计以及制造和表征这些PIC用于不同应用方面具有良好的知识和经验。

Photonic integrated circuits (ICs), first envisaged by Dr. S. E. Miller at Bell Laboratories in early 70s, have a long history but few applications. In reality, most optical systems are still built on  discrete photonic devices made of different materials by different processes. The photonic ICs are pale in terms of the density and complexity in comparison with the electronic counterpart and suffer from  compromised performance and poor yield. One of the fundamental issues in the convetional photonic ICs is the weak confinement of the optical field in  waveguiding and resonant structures with weak index contrast/variation. As such, high-density integration and strong interaction between light and media become extremely difficult. The integration and interaction are essential for realizing advanced optical signal processing functions for different applications. Therefore, the abilities to confine and manipulate optical fields on chip and to couple lights into and from chip are the key enablers for realizing robust, complex photonic ICs. The proposed research will investigate and develop high-density photonic devices and integrated circuits to perform advanced optical signal processing functions. These high-density photonic devices and ICs differ from the currently popular photonic crystal (PC) structures in the sense that the confinement, guidance and resonance of the optical fields are not due to the periodic index variation (i.e., the ``crystal effects''), but to the strong index contrast (i.e., the ``defect effects''). First of all, the research will devote substantial effort for development of efficient and accurate theoretical models and numerical techniques for simulation of the vectorial properties of the light and its strong interaction with media. In this respect, most of the existing models and simulation techniques are not sufficient;  new and improved models and algorithms need to be proposed and implemented. Secondly, basic waveguiding and resonanting structures will be examined based on consideration for absorption and scattering losses, ease of fabrication and characterization, etc. By using structures of large index contrast, we will be able to confine and manipulate light on chip by shrinking the feature size of the optical devices by a few orders of magnitude. Several strong confinement structures, e.g., the silicon wire, the deeply etched InP ridge waveguide, and the micro-ring resonator, etc., have been proposed and demonstrated. A major focus of the research is to investigate and develop novel circuit architectures to connect these waveguide and resonant elements to form complex photonic ICs. Further, we will develop efficient and accurate modeling and simulation tools for investigation of coupling between the PIC and off-chip elements. Efficient and robust mechanisms for coupling in and out of the chips will be examined. Finally, we will investigated ways for control and manipulate lights. Electrical, thermal and nonlinear effects pertinent to the materials used will be studied. The research will link closely with the on-going research in the areas of integrated optical transceivers, all optical regenerators etc. Strong collaboration with researchers at McMaster and external industrial and academic institutions will be sought and strengthened, especially in the experimental aspects to complement the expertise of the applicant. The research, if successful, will shed lights on some of the salient features of the high-density photonic ICs and advance the state-of-the-art PIC technologies towards practical applications. Several Ph.D students and PDFs will be exposed and trained in this emerging technology with good knowledge and experience on modeling, design as well as perhaps fabrication and characterizations of these PICs for different applications.