OCCR (Optical Component Coherence Reflectometer)

 

For optical connectors and components

Danger of Fiber micro crack

The condition of optical fiber soon after the fiber micro crack (Fig.1(a)) is not detected by general inspections such as IL and RL. Though, there is little gap at the point of fiber micro crack, this can be used as if it is a normal product. However, the repetition of thermal expansion and shrinkage cause the bigger gap between fibers after a long period (Fig.1(b)). It is concerned that the IL value becomes abnormal and serious performance deterioration occurs (Fig. 1 (b)). Fig.2 shows the result of temperature cycle testing of fiber micro crack product. IL value increased significantly at the timing of approximately 100 hours, in other words, temperature cycle 27th (red arrow ↑in Fig.2). This indicates the change from (a) to (b) in Fig.1. It is concerned that fiber micro crack might trigger a fatal performance deterioration of optical fiber in the future, therefore it should be eliminated.

Fig.3 is a waveform of optical connecter with a fiber micro crack measured by OCCR. Approx. 60dB reflection point is detected at the point of approx. 8mm. Fig.4 shows a SEM images of removed fiber micro crack from the optical connector. There are two sides on one fiber micro crack. One is (a), and the other one is (b). It is predicted that this fiber micro crack is occurred from bending stress by analyzing these cross sections. OCCR detects the fiber micro crack accurately.