8 Phase - Shifting Interferometry by Amplitude Modulation
نویسنده
چکیده
In optics, the superposition of two or more light beams at any point over space can produce the apparition of interference fringes. When these fringes are applied to resolve a problem in industry or they are related with some property of an investigation matter of interest in some area of physics, chemistry, biology, etc., the evaluation of them is a very necessary task. One of the most used methods for phase extraction, as a result of fringes evaluation, is based on a phase change between the interference beams by a known value, while their amplitudes are keeping constant. It is called phase-shifting interferometry, phase-sampling interferometry, or phase-stepping interferometry, which are abbreviated by “PSI” (Schwider, 1990). In this technique a set of N interferograms changed in phase are created, which are represented by a set of N equations, where each equation has three unknowns called as background light, modulation light and the object phase. These spatial unknowns are considered constant during the application of the PSI technique. Then a 3 N system is formed and therefore it can be resolved when 3 N . Many methods to introduce a constant phase have been proposed as for example by changing the optical frequency, wavelength, index of refraction, distance, optical path, for instance; but also with some properties or effect of the light such as the polarization, diffraction, Zeeman effect, Doppler effect, for instance (Schwider, 1990; Malacara, 2007). In this chapter, our major interest aims to propose a new method to generate a phase change in the interferogram based on the amplitude modulation of the electric field (Meneses-Fabian and Rivera-Ortega, 2011).
منابع مشابه
طراحی، ساخت و مشخصه یابی پله های فازی شیشه ای برای کاربرد در تداخل سنجی جابجایی فاز
In this paper, we report on the design and fabrication of a low-cost phase shifter for application in phase shifting interferometry. Phase shifting interferometry is a powerful method for surface characterization. It uses interference data recorded during a series of predetermined phase shifts to recover the induced phase by the object surface. These controlled phase shifts are typically perfor...
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