Abstract
A method of improving the band performance of fiber optic electric current measurement is described and put into test. An electric current sensing scheme with two metal-coated single-mode optical fibers in an Mach-Zehnder interferometer is employed. Experiments show that a comparatively large measurement bandwidth can be obtained by use of this method, in which only a low offset frequency component is detected, whatever the measurand frequency is. In the test experiments, we have shown a flat characteristic in frequency response up to 20 kHz. © 1998 Society of Photo-Optical Instrumentation Engineers.