Information-carrying capacity

Because optical fibers are nonconducting, fiber optic systems provide excellent electrical isolation and immunity from electrical interference. Signal losses are much lower in fibers (as low as 0.20 dB/km) compared to other guided transmission media, such as twisted copper pairs, coaxial cable, and metallic waveguides. In addition, the bandwidth or information carrying capacity of fibers is far greater. When one or more optical fibers are packaged into cables, the cables are smaller and more flexible than their metallic counterparts. 

It often seems that isotopic fractionations provide too much information about too many processes, combining it all in a package that is unmanageably intricate. In response, investigators keep increasing the complexity of the available data by providing more and more detailed analyses. The proliferation of compound-specific isotopic analyses is a prime example of this phenomenon. Does it increase the information-carrying capacity of the isotopic channel or is it another case of the triumph of entropy To obtain the preferred result, we will have to understand biosynthetic fractionations like those reviewed here. 

For common A values around 0.01, this indicates that intermodal pulse broadening is a factor of one thousand less than for step index fiber. Put in terms of information carrying capacity, the bandwidth of graded index fiber is a thousand times greater than for step index. This... 

Bandwidth The range of signal frequencies that can be transmitted by a communications channel with a defined maximum loss or distortion. Bandwidth indicates the information-carrying capacity of a channel. 

Fiber Loss Mechanisms. The two main functional parameters for optical fibers are the loss or attennation and the information-carrying capacity. In the following sections, these two aspects of the fibers will be discnssed. Normally attenuation CC expressed in nnits of dB/km is defined as ... 

The information-carrying capacity of an optical fiber is determined by its impulse response. The impulse response and hence the bandwidth are largely determined by the modal properties of the fiber. As single-mode transmissions avoid modal dispersion, modal noise, and other effects that occur with multimode transmissions, single-mode fibers can carry... 

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