Narrowband silicon waveguide Bragg reflector achieved by highly ordered graphene oxide gratings.

Graphene oxide (GO) ultrathin film can be wafer-scale deposited by spin coating, can be patterned by laser interference lithography and oxygen plasma etching, can be thinned atomically (0.26 nm/min) and oxidized by ozone treatment, and is a relatively transparent and low-refractive-index material compared to pristine graphene. All those unique properties prompt us to realize a low-loss (∼5  dB/cm), high-extinction-ratio (19 dB), and narrowband (0.

Effective Synthesis of Highly Oxidized Graphene Oxide That Enables Wafer-scale Nanopatterning: Preformed Acidic Oxidizing Medium Approach.

Demand for rapid and massive-scale exfoliation of bulky graphite remains high in graphene commercialization and property manipulation. We report a procedure utilizing "preformed acidic oxidizing medium (PAOM)" as a modified version of the Hummers' method for fast and reliable synthesis of graphene oxide. Pre-mixing of KMnO and concentrated HSO prior to the addition of graphite flakes enables the formation of effectively and efficiently oxidized graphene oxide (EEGO) featured by its high yields and suspension homogeneity.