Patent ID: 6278523
Filing Date: 2001-08-21
Classification: A61B

Abstract:
A sensor for measuring diffusion of a fluorescent marker in cavities, the sensor comprising a Mach-Zehnder micro-interferometer having a reference arm and a measurement arm, wherein the reference arm has a deposit of a sensitive layer whose refractive index is modified when the sensitive layer is in contact with the fluorescent marker, a diode laser configured to generate a source beam, a substrate of silicon micro-machined with two Y junctions, wherein a first Y junction is configured to divide the source beam into a measurement beam along the measurement arm and a reference beam along the reference arm, a piezo-electric transducer configured to shift the frequency of the reference beam in phase by an acoustic modulation, wherein a second Y junction combines the measurement beam and the shifted reference beam to generate a combined beam, and a photo-detector configured to detect the combined beam.