Patent ID: 6137573
Filing Date: 2000-10-24
Classification: G01D,G01K,G01L

Abstract:
A sensor system (10) including interferometric means incorporating sensor and reference elements (12, 58) arranged to receive broadband radiation, means for introducing a variation in optical path difference (56) between a first optical path (140) incorporating the reference element and a second optical path (120) incorporating the sensor element, means for combining the light from the first and second optical paths (120, 140) to form interferograms and signal processing means (84) to process interferogram informationcharacterised in thatthe sensor and reference elements (12, 58) are each arranged to support at least two different eigenmodes of radiation; the sensor system (10) is arranged to generate at least two interferograms therefrom; and the signal processing means (84) are arranged to extract optical group delay information from the interferograms and to derive temperature and/or strain data therefrom.