Patent ID: 7333211

Claim:
A process for determining a qualitative characteristic of a stimulus of interest in a localised environment, the process comprising: (A) providing an interferometric component capable of exhibiting a measurable response to a change in the localised environment caused by the introduction of or changes in the stimulus of interest; (B) introducing the stimulus of interest into the localised environment; (C1) irradiating the interferometric component with electromagnetic radiation of a first wavelength to generate first interference fringes; (C2) irradiating the interferometric component with electromagnetic radiation of a second wavelength to generate second interference fringes; (D1) measuring a non-positional characteristic of the first interference fringes; (D2) measuring a non-positional characteristic of the second interference fringes; and (E) determining the qualitative characteristic of the stimulus of interest in the localized environment from the non-positional characteristic of the first interference fringes and the non-positional characteristic of the second interference fringes.