Fiber Optics

Fiber optics deals with light propagation through this glass fiber. Fiber optics plays an important role in the field of communication. The transmission of light via a dielectric wave guide structure was first proposed of investigated at the beginning of the twentieth first century. A transparent dielectric rod, typically of silica glass with refractive index 1.5, surrounded by air, proved to be an impractical wave guide due to its unsupported structure of excessive losses at any discontinuities of glass air interference. Nevertheless, interest in the application of dielectric optical wave guides in such areas as optical imaging and medical diagnosis led to the proposal of clad, surrounding the glass.

Light energy travels in both the core of cladding allowing the associated fields to decay to a negligible value at the cladding air interface. Loss is about 100 dB/Km. Tremendous efforts to reduce the attention by purification of the material in which loss was about 4.2 dB/Km. most of this work was focused on 0.8 to 0.9 µm wave length band, because the first generation optical sources fabricated from gallium Aluminum Arsenide operates in this region. However, as silica fibers, were investigated at longer wave length (1.1 to 1.6 µm) resulted in lower losses of reduced signal dispersion. Around 1.55 µm, fiber loss =0.2 dB/Km. Recent regions Mid IR (2 to 5 µm) and IR (8 to 12 µm). For transmission mechanism of optical fibers with dimension approximate to that human hair, it is necessary to consider it as a cylindrical glass fiber. Such fiber acts as an open wave guide, which may be analyzed utilizing simple say theory. Discussion of light propagation in optical fibers using ray theory approach is essential in order to develop some of fundamental parameters associated with optical fiber communication.