IndexThe architecture of OTDDRWorking of OTDRFunctions of an OTDRFunctions of an OTDRFunctioning of an OTDRApplication of the OTDROTDR stands for optical time domain reflectometer. An OTDR requires scattered light in the fibers to locate faults. Traditionally FTTH PON maintenance and troubleshooting is performed via external OTDR equipment. This approach requires new fibers to be connected to the optical distribution network. It shows that the OTDR records the light reflected from the fiber and head over time. The OTDR works from one end and produces a "picture" of the cable. The connected fiber is known as launch cable. We can work with a single launch cable and have some information with the receive cable. Say no to plagiarism. Get a tailor-made essay on "Why Violent Video Games Shouldn't Be Banned"? Get an original essayThe architecture of the OTDDR is the most important examination tool for fiber optics, applicable for measuring fiber loss, connector loss, and determining the exact location and value of cable discontinuities. Using very short pulses, the modal dispersion of multimode fibers can also be measured. The structure of a typical OTDR equipment is shown below:Working of the OTDRThe principle of the OTDR analyzer is that a short light pulse is transmitted into the fiber under test, and the incidence time and amplitude of the reflected pulses are measured. The commonly used pulse width ranges from nanoseconds to microseconds, the pulse power can exceed 10 mW. The repetition frequency depends on the length of the fiber, typically it is between 1 and 20 kHz, naturally it is lower for longer fibers. Division by 2 at the oscilloscope inputs is necessary because both the vertical (loss) and horizontal (length) scales correspond to one-way length. Types of OTDR There are currently three forms of OTDR on the market. 1-Laboratory OTDR: Laboratory OTDRs are usually used in testing laboratories. They have an especially long range with many options.2-Mini OTDRs: Mini OTDRs are portable and designed for fluid analysis.3-PC Computer-based OTDRs: PC-based PCs connect to your personal computer and run software based on Windows.An OTDRFast Automatic Test Functions: The automatic test function provides quick results without knowing much information about the equipment. Connect the fiber first and then press "Test" button, it will automatically set the optimal test and show accurate test results, such as test curve and event lists. Quick Curve Analysis: It can find the failure point in the test curve and also find the location information in the same curve test. Keep a list of all events that occurred during the test. Powerful Document Management: Provides store viewing, deleting and saving function using PCL language based software. Convenient VFL function: Using this function we can easily discover disconnection points in short-distance fiber optic links. Manual test mode: There are two modes, real time or average time. Fast testing in real-time mode compared to dynamic testing. Average Test Mode: Average test mode is used to withstand noise in test curves to the maximum extent, to achieve more accurate test results. The operation of an OTDROTDR uses Rayleigh scattering and Fresnel reflections on the characteristics of portioned fibers. Rayleigh scattering refers to the approximate scattering produced by the transmission of optical signals in the fiber..