Optical metrology is the technique of analysing the interaction of light with any object to measure unknown quantities. The measurement is done by first considering the transmission of light without any obstacle in place and then comparing the same with the results of the transmission of light when there is an object placed in its path. This makes metrology ideal for applications where physical contact is not possible with the object in question. Optical metrology uses different sources of light for different applications. The different light sources include broadband, lasers and narrowband light sources. The light rays are then receieved and the data thus obtained undergoes processing, where it is analysed. Optical metrology can be used for measurement requirments where physical contact is not required but more importantly, it can be used for aplications where a specific point of a sample needs to be analysed against other points within the same sample itself. As such, there has been...