Low Coherent, High Resolution WDM Reflectometry for Fiber Length Measurement
Project Award Date: 12-01-2000
This project aims to test a method that measures the path length in an optical fiber accurately and dynamically. This method combines the traditional low-coherent reflectometry implementation with modern wavelength-division multiplexing (WDM) technology. This is accomplished through a string of optical fiber gratings; each fiber grating reflects a specific wavelength band. This string of fiber gratings will act as a wavelength-dependent optical delay line, and perform wavelength-domain-to-time-domain conversion of the optical signal. This technique is superior to the existing measurement methods in that it provides sub-millimeter spatial resolution and 1m dynamic range.
The focus of this project is on the measurement of earth Crustal deformation. This will be accomplished by burying the fiber under ground and measuring the length variation of the fiber. Since Crustal deformation causes the surface of the Earth to change constantly, this deformation can be seen as the sole reason for earthquakes and volcanoes. Using the proposed fiber-optic WDM optical low-coherent reflectometer, the Crustal deformation may be accurately monitored; it will be measured and active faults in the Manhattan, Kansas area will be identified.
Expectations of this project include the development and optimization of methods for data acquisition and processing. The successful completion of this project is predicted to provide the geophysical community with an unprecedented tool for the study of many theoretical and practical problems.
Primary Sponsor(s): NSF/KTEC