Patent ID: 9029782
Filing Date: 2015-05-12
Classification: G01N,G02B

Abstract:
1. Apparatus comprising: at least one lightguiding element having an optical core; wherein the lightguiding element comprises a layer of graphene situated in sufficient proximity to the core to exhibit evanescent wave absorption of optical energy in at least one optical mode guided in the core, the lightguiding element is one of two or more lightguiding elements, each having a core and a graphene layer in proximity to the core, each lightguiding element is optically coupled to an optical source arranged to inject light into said element and an optical detector arranged to measure optical loss by detecting light coupled out of said element, one or more diffusion layers of aerogel overlay the graphene layers of one or more respective lightguiding elements, and at least one lightguiding element has no diffusion layer or at least two lightguiding elements have diffusion layers of different thicknesses.