This paper describes the optical fiber cabling system you may be a lot of people do not know the cable wiring system, does not matter, I believe you are reading this fiber cabling system will have a rough understanding, hope this will teach you more things.
Fiber cabling system installed after the transmission characteristics required to test the link, most notably several test projects link attenuation, connector insertion loss, return loss and so on. The following cable wiring system, we have the key physical parameters of the measurement and network troubleshooting, maintenance, and so a simple introduction.
First, the key physical parameters of fiber optic cable link
Attenuation:
1, attenuation of light along the optical fiber transmission to reduce the optical power.
2, the total attenuation of the fiber-optic network computing: Optical loss (LOSS) is the optical output power Power out and launched into optical fiber power Power in the ratio.
3, with the fiber loss is proportional to the length, so the total attenuation loss not only show that the fiber itself, but also reflects the fiber length.
4, cable loss factor (α): To reflect the characteristics of optical fiber attenuation, we introduce the concept of cable loss factor.
5, on the attenuation measurement:
Because the optical fiber connected to the light source and optical power meter that will inevitably introduce additional loss. Therefore, field tests must be conducted when the test apparatus the test set reference point (ie zero setting). Reference point for the test There are several ways, mainly according to the link object to test the methods of choice in optical fiber cabling system, due to the length of fiber is usually not long, so the test methods will be more emphasis on Lianjie device and test jumpers, the method is more important, on this point see the wiring test Arnhem technical articles.
Return Loss:
Return loss is also known as return loss, which refers to fiber-optic junction, then the reflected light relative to the ratio of input light decibels, the greater the return loss the better, to reduce the reflected light on the light source and system. Improve the return loss is to try to use the fiber end processed into spherical or helical sphere is an effective way to improve return loss.
Insertion Loss:
Fiber insertion loss is through the activities of the optical signal connector, the relative output optical power ratio of input optical power decibels;
Insertion loss smaller the better;
Measurement of insertion loss attenuation measurements with the same way;
Second, fiber optic network test and measurement equipment
1, optical fiber identifier.
It is a very sensitive photodetector. When you bend an optical fiber, some light will come from the core is the radiation. The light will be detected by optical fiber identifier, technical staff can be the basis of these multi-core optical fiber, or patch panel in a single fiber out from the other fiber identification. Fiber Identifier can not affect the transmission of light under the state and direction detection. To make this work more simple, usually to test the transmitter signal modulated 270Hz, 1000Hz or 2000Hz and into a specific fiber. Most of the optical fiber identifier for 1310nm or 1550nm wavelength of single-mode optical fiber cabling system, the best optical fiber identifier can be used to identify the macro-line bending technology and test optical fiber transmission in the direction and power.
2, fault locator (fault tracking device).
This device based on visible laser diode (red light) source, when the light into the fiber, if fiber fracture occurs, the connection failure, bending over, poor weld quality similar breakdown, by launching into the optical fiber on the fiber can visual fault localization. Visual fault locator to continuous wave (CW) or pulsed mode of emission. The typical frequency of 1Hz or 2Hz, but can also work in the kHz range. The usual output of 0dBm (1Mw) or less, working distance of 2 to 5km, and supports all the common connector.
3, optical loss test equipment (also known as optical multimeter or power meter).
To measure the loss of a cable link, need to end the stability of light emission calibrated and read out at the receiver output power. The devices constitute optical loss tester. The synthesis of a light source and power meter instrument, often referred to as optical loss test set (which was also known as optical multimeter). When we measure the loss of a link, you need to have a transmitter operating in test light source and another person with the power meter to measure the receiving end, this still only a direction of the loss of value.
Usually, we need to measure the loss of two directions (because the existence of the connection loss, or the cable transmission loss that is due to the asymmetry induced). At this time, technicians have to exchange equipment and to conduct other direction measurements. However, when they are separated by more than a dozen floors or when dozens of kilometers of how to do? Obviously, if two individuals each have a light source and a power meter, then they can be measured simultaneously on both sides, Now the test for certification testing advanced fiber cabling system is a set of machines can achieve two-way dual-wavelength testing, such as: Fluke's CertiFiber and DSP series cable testing cable wiring system testing FTA package.
In short, to complete a light loss measurements, a calibration of the light source and a standard optical power meter is indispensable. More detailed technical information please refer to An Henggong Division wiring test instruments related products category.