ABSTRACT
This chapter observes an interference pattern in both reflection and transmission. The optical path difference is assumed to be constant for the two wavelengths under consideration. The wavelength of the incident radiation remains constant, and hence the path difference between two beams in the interferometer is constant with time the interference pattern remains stationary. However, if the object is accelerating, there is a change in phase difference. Radiation from a semiconductor laser is coupled to a single-mode fiber. It is therefore worth commenting that interference does take place when two monochromatic waves of slightly different frequencies are superposed. Part of the radiation is extracted into a fiber by a directional coupler, thereby creating two beams. The fiber ends can be separated by a desired amount, and a large lens focuses the beams in the sample volume.
