Binary SuperGrating Optics - An Enabling Concept and Explorations

二元超栅(BSG)是一种新型的导波器件：波长选择性光学器件，它提供定制的WDM滤波、WDM耦合/布线、波前和光谱整形。从概念上讲，BSG可以看作是Bragg光栅向频率空间的延伸，就像光子带隙概念可以被看作是Bragg光栅向3D实空间的延伸。BSG采用简单的两级等尺寸实施，将这一约束转化为资产：制造公差大大降低，性能几乎不受工艺非线性和缺陷的影响。BSG概念可以很容易地应用于各种光学设备和功能，具有极大的改进，而且往往是前所未有的性能特征。我们建议在我们的第一个概念和实验演示的基础上，将BSG概念发展为一种使能技术，用于广泛类别的波长选择设备。利用无源通道波导，我们将综合数字信号处理技术实现BSG设计，并探索相应的性能极限。在有源区，我们将实现自准直多波长激光器(SCMWLS)，以研究具有复折射率的BSG行为。我们还将开发图案转移方法，以实现BSG设备的大规模生产，促进行业接受。我们希望，这些努力将产生充分利用这一令人振奋的新技术所需的扩大了解。

The Binary SuperGrating (BSG) is a novel concept enabling a new class of guided-wave devices: wavelength-selective optics, which offers customized WDM filtering, WDM coupling/routing, and wavefront and spectral shaping. Conceptually, BSG can be regarded as an extension of the Bragg grating to frequency space, much like the photonic bandgap concept can be viewed as an extension of the Bragg grating to 3D real space. The BSG utilizes a simple two-level equal-size implementation, turning this constraint into an asset: fabrication tolerances are greatly eased, and performance is virtually immune to process non-linearities and defects. The BSG concept can readily be applied to a wide variety of optical devices and functionalities, with greatly improved and often unprecedented performance characteristics.We propose to build on our first conceptual and experimental demonstrations, to develop the BSG concept into an enabling technology for a broad class of wavelength-selective devices. Using passive channel waveguides, we will implement BSG designs synthesized with techniques adapted from digital signal processing, and explore the corresponding performance limits. In the active regime, we will implement self-collimated multi-wavelength lasers (SCMWLs), to examine BSG behaviour with complex refractive index. We will also develop pattern-transfer methods that would permit mass-production of BSG devices, facilitating industry acceptance. It is our hope that these efforts will produce the broadened understanding necessary to take full advantage of this exciting new technology.