NEW DISTRIBUTED FIBER OPTIC SENSORS BASED ON COUNTERPROPOGATING WAVES

A NOVEL, FIBER-OPTIC APPROACH IS TAKEN IN THIS PROJECT TO THE DISTRIBUTED SENSING OF FORCES AND TEMPERATURES SIMULTANEOUSLY AT DIFFERENT LOCATIONS WITH A SINGLE LONG OPTICAL FIBER PROBE. THIS CONCEPT USES TEMPERATURE-AND/OR FORCE-DEPENDENT STIMULATED LIGHT AMPLIFICATION PROCESSES AT EACH SENSING POINT ALONG THE FIBER PROBE. THE APPROACH IS DESIGNED TO GENERATE, AT EACH SENSING POINT ALONG THE FIBER, OPTICAL SIGNALS UNAFFECTED OR ONLY MINIMALLY AFFECTED BY THE MAGNITUDE OF THE FORCES AND/OR TEMPERATURES AT OTHER POINTS ALONG THE FIBER. IN CONTRAST TO PRESENTLY KNOWN METHODS, OUR APPROACH DOES NOT REQUIRE MEASUREMENTS OF THE STATE OF POLARIZATION OF THE LIGHT AT ANY POINT ALONGTHE FIBER PROBE, AND IT SHOULD BE IMPLEMENTABLE WITH RELATIVELY SIMPLE INSTRUMENTATION. A NOVEL, FIBER-OPTIC APPROACH IS TAKEN IN THIS PROJECT TO THE DISTRIBUTED SENSING OF FORCES AND TEMPERATURES SIMULTANEOUSLY AT DIFFERENT LOCATIONS WITH A SINGLE LONG OPTICAL FIBER PROBE. THIS CONCEPT USES TEMPERATURE-AND/OR FORCE-DEPENDENT STIMULATED LIGHT AMPLIFICATION PROCESSES AT EACH SENSING POINT ALONG THE FIBER PROBE. THE APPROACH IS DESIGNED TO GENERATE, AT EACH SENSING POINT ALONG THE FIBER, OPTICAL SIGNALS UNAFFECTED OR ONLY MINIMALLY AFFECTED BY THE MAGNITUDE OF THE FORCES AND/OR TEMPERATURES AT OTHER POINTS ALONG THE FIBER. IN CONTRAST TO PRESENTLY KNOWN METHODS, OUR APPROACH DOES NOT REQUIRE MEASUREMENTS OF THE STATE OF POLARIZATION OF THE LIGHT AT ANY POINT ALONGTHE FIBER PROBE, AND IT SHOULD BE IMPLEMENTABLE WITH RELATIVELY SIMPLE INSTRUMENTATION.