Patent ID: 7869044

Claim:
An optical sensing system, comprising: an optical sensor comprising a substrate having a substantially flat upper surface, wherein the optical sensor comprises a plurality of tapered walls protruded above the substantially flat upper surface of the substrate, wherein at least one of the tapered walls is aligned along a longitudinal direction, wherein at least one of the plurality of tapered walls comprise a lower portion having a first sloped surface relative to the upper surface and an upper portion having a second sloped surface relative to the upper surface, wherein he first sloped surface and the second sloped surface have different oblique angles relative to the upper surface of the substrate, wherein the sloped surfaces are configured to adsorb molecules of a chemical sample; a light source configured to emit an incident light beam to impinge the plurality of tapered walls adsorbed with molecules of the chemical sample; and a detector configured to collect light scattered by the plurality of tapered walls to enable a determination of the sample chemical.