Write 26 pages with APA style on Light Background and Interferometry. The interferometry technique has exceptionally many possible setup metrologies for in-process surface measurement and this chapter demonstrates the basic concepts for the various types. Some of the basic keywords and concepts introduced include the fundamental of light, interferometry, short coherence scanning tomography, fringe pattern analysis, and evaluation of some of the recent techniques used in the inspection of surface instrumentation. Until the mid-nineteenth century, the accepted idea of light had remained to be the substance particle phenomena. In this perspective, recommended by Newton, light consideration has been that of very small particles. However, in the late nineteenth century, the new perception of light in terms of wave theory replaced the particle phenomena and still remains. The inception of wave theory firmly and accurately stated that light has energy especially because of its characteristics of refraction, diffraction, and interference. These three properties of light are definable only using the wave pattern, unlike the particle phenomena, and depend on the experiment setup and apparatus used. When defined under wave phenomena term (wavelength), light is a form of electromagnetic energy made of very tiny particles that fall within the broad electromagnetic spectrum (see Figure 3.1).There are two types of light, monochromatic and non-monochromatic. Monochromatic light is light made of a single wavelength such as laser hence the word mono refers to one. Conversely, non-monochromatic light is any light source with broadband comprising of multiple wavelengths with varying electromagnetic frequencies. No light has a definite single frequency. However, light has numerous wavelengths of varying frequencies because it has a bandwidth ?f as shown in the table below. For this reason, light sources have multiple applications (Kempe, 2007, p. 24).In short, optics demonstrates technological innovation in the study of light. This is because it involves studying light using lens-equipped instruments to detect electromagnetic radiation for the attainment of accurate long-range vision. . .