Combined Effect of all Noises in Optical Fiber


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this ppt help to understand different types of noises in optical fiber communicaions.


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Combined Effect of all Noises in Optical Fiber Commnucation : 

Combined Effect of all Noises in Optical Fiber Commnucation Jagtar Singh Regd. No- 11011161 Roll No. – RG2001A03


NOISE noise  is a random fluctuation in an signal or it is disturbance in signals. Noise is an error or undesired random disturbance of a useful information signal, introduced before or after the detector and decoder. It is a summation of unwanted or disturbing energy from natural and sometimes man-made sources

Noise in OFC : 

Noise in OFC Noise in OFC is of two types Optical Electronics

Optical Noise : 

Optical Noise Modal Noise It aeries when monochromatic light is coupled into a multimode fiber, it is due to mechanical disturbances like vibrations, connector splices and microbends. Due to intramodal disperssion in optical fiber there is frequency fluctuation which also cause modal noise

Optical Noise : 

Optical Noise Mode partition noise It is associated with intensity fluctuations in the longitudinal modes of laser diode. This is dominant in single mode fibers Chipring This is due to line broadning of source i.e. for laser when injection current varies this cause wavelength distribution.

Optical Noise : 

Optical Noise Reflection noise When light travel in optical fiber some light get reflected back at refractive index discontinuities such as splices , couplers and filters or at air glass intrferance in connectors.

Electronics Noise : 

Electronics Noise These days optical amplifiers are used in optical fiber communication to amplify the signals. As electronic amplifiers do optical amplifiers add noise to the signal they amplify. Thermal (Johnson) noise It generated by the random thermal motion of charge carriers (usually electrons) inside an electrical conductor, which happens regardless of any applied voltage.

Electric Noise : 

Electric Noise Shot Noise Shot noise in electronic devices consists of unavoidable random statistical fluctuations of the electric current in an electrical conductor. Random fluctuations are inherent when current flows, as the current is a flow of discrete charges (electrons).

Electronics Noise : 

Electronics Noise Flicker noise Flicker noise is a signal or process with a frequency spectrum that falls off steadily into the higher frequencies, with a pink spectrum. Avalanche noise Avalanche noise is the noise produced when a junction diode is operated at the onset of avalanche breakdown.

Slide 10: 

Apart from these noises there is noise due to detector or receiver. The is usually a photo detector i.e. a photo cell. This is a device which convert optical signals back to electric signals. As this is a electronics device this will also add noise to signal.

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Questionnaire ?

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