Abstract

A distributed optical fiber leakage sensor is disirable for a fuel tank and pipeline because of the safty from explosions. As a method of direct sensing, the use of the evanescent field tail of the light wave is considered. Lew et al.¹ have made an all-fiber single-mode absorption spectroscopic sensor by the use of polished fiber, operating as a point transducer. Tanaka et al.² have demonstrated an fiber-optic evanescent wave gas spectroscopic sensor. Since the cladding diameter of the sensing part is less than 10µm, it is too hard to hold the fiber.

© 1986 Optical Society of America