Factors affecting the quality of compact fiber optic fiber and its solution

AddTime£º29-09-2016   Author£ºadmin

The temperature characteristic of tight sleeve coating material is the key factor to influence the tight sleeve fiber, and also the problem that must be considered in making tight fiber. Because the coating sleeve temperature characteristics of optical fiber and optical fiber itself except the structure parameters and performance of micro resistance but also associated with the performance of second coating materials of the fiber, the plastic sleeve, due to solidification, nylon, polyethylene and other plastics will shrink, resulting in a contraction of external force in a coated fiber, will the optical fiber micro bending, resulting in the increase of the optical fiber micro bending loss, so that the total transmission loss of optical fiber, there are two reasons for the plastic shrinkage.

(1) SiO2 bare fiber glass fiber, a=5*10-7/ temperature linear expansion coefficient of Sio2 material, and the plastic coating material linear expansion coefficient of a=5*10-4/ temperature difference of three orders of magnitude in the cooling temperature change, plastic will produce a contraction effect to fiber, the fiber attenuation increases.

(2) the set of compact fiber coating processing, remains part of the internal stress in the plastic layer, when the fiber is affected by temperature occurs, relaxation caused by internal stress (excretion), or stored at room temperature, with the extension of storage time, the stress will also slow relaxation, make the coating shrinkage sleeve that leads to the microbending loss increase.

In order to reduce the additional loss due to plastic process caused by the following aspects should be considered to solve this problem

And should use the linear expansion coefficient of the material is similar to that of SiO2 coating material coating layer to replace the silicone resin, nylon and other materials. Or select the linear expansion of small, low elastic modulus of coatings, but if the material in the two aspects of the performance is too low, the compressive properties of it will be significantly decreased, so it is necessary to consider the two aspects of the index, select material as coating material of moderate elastic modulus.

Sleeve, choice technology, mold to maintain smooth, and select the appropriate plasticizing temperature, and cooling rate, plastic extrusion speed and traction speed than the fiber to achieve the best, try to avoid the set of plastic optical fiber vibration to eliminate stress fiber residue, strictly control the cooling temperature.

Reduce the cross-sectional area of the coating. When several dimensions of the optical fiber are fixed, the cross section area of the coated layer is larger, the temperature of the coating fiber is more poor, and the method of using second kinds of process is recommended.