Attenuation measurement of infrared optical fibers by use of a hollow-taper-based coupling method

An alternative method for attenuation measurement of infrared (IR) fibers i s described. The method includes a simple technique for direct laser-to-fib er coupling with an uncoated glass hollow taper. The operating principle of the hollow taper is based on the grazing-incidence effect of light reflect ion. The hollow taper forms a smooth Gaussian-shaped profile of the output laser emission and provides the proper conditions for equilibrium-mode dist ribution of optical power within the test IR fibers. The experimental hollo w-taper-based coupling method is used for measurement of attenuation and be nding losses of various kinds of IR fiber, including solid-core (fluoride, chalcogenide, and germanium-doped) and hollow fibers. (C) 2000 Optical Soci ety of America. OCIS codes: 060.2340, 060.2310, 060.2280.