Optical time-domain reflectometer

There are two types of index of refraction values which are of interest. The first is the phase index value, which indicates how fast the phase of the Hght is traveling. This lOR value is used in essentially aU of the related transmission equations, except for transit time. The second index value relates to how fast power travels down a fiber. This index value, called the group index, is the one of interest in determining transit times, and is the value employed when using an optical time domain reflectometer for distance calculations. The group index is often referred to as tig and can be calculated from the phase index using the equation... 

Less than 1% of the scattered light is reflected back, or backscattered, toward the transmitter source, and it is this effect that forms the basis by which optical time domain reflectometers (OTDR) operate. The OTDR is an important tool in fiber optics and is the piece of equipment most commonly used for... 

OTDR optical time domain reflectometer optical time domain reflectometry... 

The distributed signals can be measured and spatially resolved by an optical time-domain reflectometry technique. An optical time domain reflectometer is based on the measurement of backscattered light attained from a light pulse propagating through an optical fiber. Light is backscattered because of inhomogeneities and impurities... 

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