Optical fiber in in place of the related technical problems,

in the single mode fiber is working at a given wavelength, only the single mode optical fiber. He does not exist mode dispersion, so the single mode fiber is quite wide transmission band, applied to long distance, large capacity transmission. Single-mode fiber core classics is very fine, only 8 - fiber core diameter 10 mu м, cladding diameter is 125 mu м, can make for a very long, but for the manufacture, transportation, construction is convenient, usually the cable length is 1 - factory - - - - - - 6㎞。 Single mode fiber low transmission loss is now up to 0. 2 db /㎞ 1. 55μм) ㎞, optical fiber length not less than 2. In the fiber connection, generally in accordance with the following procedures: (1) set in advance on the optical fiber in optical parts for reinforcing with steel wire heat shrinkable casing; Remove the coating layer, covering pliers vertical clamped fiber strip 20 mm - quickly - A 30 mm long coating and the second coating layer, soaking with rubbing alcohol cotton ball or lens paper fiber, the fiber core is wiped clean, and pay attention to the surface of the fiber should not be split, scratches. (3) cutting fiber, making face in the fiber connection, the end of the optical fiber production processes is the most critical. The optical fiber end is perfect or not decided one of the main reasons for loss of fiber connection. It requires preparation after the end face of level off, without burr, without defect, and with vertical axis, present a smooth and flat mirror surface area, and keep clean, prevent dust pollution. Preparation end there are three ways, one is the indentation method, adopts mechanical cutting knife, with a diamond knife on the surface of the perpendicular to the direction of the fiber cross notch, from 10 ㎜ coating layer, gently touch, fiber optic notch location on the natural fracture, 2 it is cutting pliers method, it is the use of a self-made simple holding forceps for cutting operation. Three is the ultrasonic electric cutting method. These three methods as long as the equipment is good, operation is proper, the effect of the preparation of end face is very good. (4) to connect to the two optical fibers in the welding machine for welding, the automatic operation by the welding machine. [5] in place of the performance test using OTDR instrument several evaluation, conform to the connection index, then in the reinforcement of the protection, namely hot melt heat shrinkable tube with a wire. [6] in the end, after the stead in all fiber core, income for disc, using OTDR instrument for retest, don't want to asylum or to continue, until qualified. Single-mode fiber loss index is generally classified as 0. 08 db, in construction, the indexes according to actual conditions, but are generally not greater than zero. 08年db。