Binary SuperGrating Optics - An Enabling Concept and Explorations

Brown University, Providence RI

Investigators

Abstract

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.