What is the OTDR

Optical fiber is an important part of communication transmission, which shoulders the great mission of transmitting network signals. The performance of transmission optical fiber directly affects the reliability of communication system, and the probability of transmission optical fiber problems is relatively high, such as cable bending, fracture, etc.

Regardless of the cause, you need to quickly locate the fault, repair the optical fiber, and restore normal communication. But tens of hundreds of kilometers of optical fiber can not rely on people to find a little bit of the network, at this time you need to use the optical fiber world "radar" technology - OTDR, minutes to locate the point of failure, save time and effort and worry.

What is the OTDR?


Optical Time Domain Reflectometer (OTDR) technology is a sophisticated optoelectronic integrated equipment based on backward Rayleigh scattering and Fresnel reflection, which can measure Optical fiber length, loss, joint attenuation and breakpoint location.

Let's start with Rayleigh scattering, which is actually quite common in everyday life. For example, when we turn on a flashlight at night, the reason we see a beam of light is because the dust and fog in the air scatter the light. Some of the light enters our eyes and we see it. All the particles scatter to form a beam of light. When the fog is thick the beam will appear dense, otherwise it will appear sparse. If you're in a vacuum, you can't see the beam.

Back to optical fibers, the main component of optical fibers, SiO2 (silicon dioxide) medium, has uneven density and composition, as well as impurities, bubbles and microcurved structures, similar to dust and fog in the air. When we to the injection of a light pulse in the optical fiber link, the pulse of light energy in the process of forward transmission with uneven sedimentation, there will be a very weak energy scattered in all directions, this phenomenon is called Rayleigh scattering, one part will be totally reflected back along the route direction, after this part is called Rayleigh scattering.