Tightness estimation of fiber ribbons in a slot-type single-mode optical-fiber cable

Tightness of fiber ribbons in a slot-type cable is estimated by measuring the temperature dependence of fiber strain due to temperature change for free fiber ribbons and those assembled in a cable. Fiber-strain measurements were carried out by an optical heterodyne detection technique for free nylon-jacketed and liquid-crystal-polymer (LCP)-jacketed fiber-ribbons, and for the cabled fiber ribbons. By comparing the thermal behavior of fiber strain for both states of jacketed fibers, it is found that the fiber ribbons are tightly accommodated in the slot-type cable in temperature regions over -15°C for nylon-jacketed fiber ribbons and 0°C for LCP-jacketed fiber ribbons under additional fiber-strain value of 0.015% through the cabling process. The fiber ribbons, which are tightly accommodated with suitable tension level through the process at room temperature, show reasonable thermal-strain behavior in comparison with the initially introduced fiber strain during the cabling process