Design and Test Results of an Optical Fiber Feedthrough for an Optical Submarine Repeater

Optical Fiber Breaks Due to Buckling: Problems in Device Packaging

“…(6), the primary coating layers were removed using concentrated H 2 SO 4 so as not to introduce flaws on the fiber surfaces after the outer nylon jackets had been mechanically removed [11,12]. The Au/Ni layers of samples (5) and (6) were formed directly on the glass surface, just after the primary-coat removal, by a conventional electroless plating method. Thicknesses of the inner Ni and outer Au layers were 1-2 and 0.1-0.3 µm, respectively.…”

“…4c). The samples (6), in which the coating layer was chemically etched and removed, were stronger than the coated samples (5), suggesting that the Au/Ni plating treatment itself was not a dominant factor of fiber weakening. In regard to the low strengths of the Au/Ni-coated fibers, two possible reasons could be con-…”

“…A weakening in such fibers (6) rather than in the untreated fibers (4) could be attributed to the fact that surface roughnesses are possibly introduced by chemical treatments in the plating process. Figure 7 shows the surfaces of the fibers before plating (a) and after etching the plating layers (b), corresponding to samples (4) and (6), respectively, observed by AFM. Their surface roughnesses R z were 2.01 nm for (4) and 3.96 nm for (6).…”

“…Figure 7 shows the surfaces of the fibers before plating (a) and after etching the plating layers (b), corresponding to samples (4) and (6), respectively, observed by AFM. Their surface roughnesses R z were 2.01 nm for (4) and 3.96 nm for (6). The strength ratio of (6) to (4) samples was estimated to be 0.713 from their surface roughnesses using Griffith's law and it was almost in agreement with the 0.877 derived from the characteristic D values in this experiment.…”

“…For undersea devices, many sealing techniques where the metalized fibers and tension members are bounded together with the solder into the feed-through pipes have been proposed [1][2][3][4]. Yamazaki et al reported a reliable design for the undersea repeater, which is based on a copper and gold metalization technique of the fibers coated with a very thin polyimide layer [5,6]. The undersea high isotropic pressures and almost isothermal conditions are advantageous to maintaining the structural stability of packages, assuming that the moisture penetration problems are successfully solved.…”