Sagnac interferometric sensor array
Sagnac interferometric sensor array
Applicant: Korea Advanced Institute of Science and Technology, KoreaPatent number: US6,208,590Publication date: 27 March 2001Title: Sagnac interferometric sensor array for acoustic sensing and method of detecting acoustic signalsKeywords: Acoustics,Sensors, Patents
A Sagnac interferometric sensor array for acoustic sensing and a method of sensing acoustic signals is presented, in which the system is able to observe acoustic signals coming from several sources simultaneously. The invention suggests a way of fabricating an array of fiber-optic acoustic sensors that is easy to be made and is highly sensitive at a given frequency band.
The acoustic sensor described is a Sagnac interferometric sensor array employing a depolariser. Unlike a single Sagnac interferometric sensor, two light signals travelling in the opposite directions from each other pass through the off-centre position of the loop at different times in the Sagnac loop when they are pulses, and thus, it is possible for the light pulses to be maintained at a constant phase difference by giving arbitrarily a certain amount of phase to them. The interferometer is constructed in such a way that the interference light output coincides with the applied acoustic signals in waveform and without any complex electrical signal processing.
Jon Rigelsford
