1. Fiber coating material selection and drawing process
The reasons for the increase in fiber loss mainly include hydrogen loss, fiber cracking, and fiber stress. After actual use, it has been found that the optical properties of the fiber optic cable have not changed substantially after being used for many years, such as geometrical characteristics, mechanical properties, continuation characteristics, and optical properties. It was found by scanning electron microscopy and the like that the optical fiber has no obvious microcracks and the like. However, the fiber coating condition is significantly different. The fiber with high modulus, tight coating and high peeling force has a significant increase in attenuation at 1550 nm and 1310 nm.
Second, the grease filling design
The fiber paste is an oily substance in close contact with the optical fiber. It is a mixture based on mineral oil or synthetic oil. It is used to isolate water vapor and lubricate the fiber. The performance of the fiber paste is evaluated by visual observation of the morphology and the oxidation induction period of the test ointment. The increase of acid value after oxidation of the ointment can lead to an increase in hydrogen evolution. At the same time, the oxidation of the ointment has an effect on the stability of the cable structure, resulting in a decrease in yield stress, so that the fiber is affected by vibration, impact, bending, temperature difference, topographical geological changes, etc. It will be stressed and weaken the buffering effect of the fiber paste on the fiber, thus reducing the reliability of the cable.
The direct contact of the fiber paste with the fiber is the most important indirect cause of the deterioration of the fiber performance.
Through the actual detection of the in-use optical cable produced in different periods, it was found that the fiber paste slowly denatured with time. Usually it is first assembled into small particles, which are then gradually volatilized, decomposed, and dried. For direct buried or pipeline cables in central China, the typical time for the fiber pulp to begin to degenerate significantly is 18 years.
Third, the size of the loose tube
The effect of the size of the loose tube on the life of the cable is more reflected in the overall stress. When the size is too small, under the variation of temperature, mechanical stress, interaction between the filler and the fiber, the stress on the fiber is not relieved, and the attenuation of the fiber is increased, resulting in aging.
Cavity Band Pass and Band Stop Filter
Cavity Band Pass Filter & Band Stop Filter, High [Q" design for Narrow BW, Low insertion loss and High rejection. From 200MHz to 40GHz, Connector SMA, N, 2 92mm or Drop-in are available. Power handling from 0.5 to 2000Watts. Customized frequency and optimized specifications available, Contact us with your requirement
Cavity Bandpass Filter,Variable Bandpass Filter,Cavity Band Pass Filter,Microwave Band Pass Filter
Chengdu Zysen Technology Co., Ltd. , https://www.zysenmw.com