A relatively short-term transient mechanism of increasing optical fiber attenuation from the presence of hydrogen (H2) has been observed in single-mode optical fibers. The attenuation increases have a distinctive pattern of spectral absorption peaks. Peaks at 1.25, 1.53, and 1.64 μm are predominantly transient, whereas peaks at 1.33, 1.38, and 1.44 μm are predominantly permanent (Fig. 1). The magnitude of attenuation increases correlation with excess absorption at 0.63 μm (Fig. 2) reflecting the number of active detect sites susceptible to the phenomenon. The product of excess absorptions1 at 0.24 and 0.63 pm is believed to be a constant. The defect sites can be in either or both the core and cladding of the fiber.
© 1987 Optical Society of AmericaPDF Article