Electronic Speckle-shearing Pattern Interferometry Based Square Prism And The Analyse Of Phase-shifting Measurements

Speckle metrology is an important branch of optical measurement techniques. Speckle techniques make use of laser speckles formed in space or artificial speckles deposited on the specimen surface to monitor displacement or to carry out deformation measurement. In the past three decades, in addition to the study of the inherent properties of laser speckle fields, various speckle measurement techniques are gradually developed and widely applied in different fields.Electronic speckle pattern interferometry , which uses fringe analysis for nondestructive deformation field measurements, has become an important technique in the recent 20 years. Electronic Speckle-shearing Interferometry is a new method which developed from Electronic speckle pattern interferometry .The method has many advantages of the whole-field measurement, the simple optical road, the easy modulation and the low demand for environment. The phase-shifting method which is used in ESSPI can improve the precision of the measurement greatly. So the phase-shifting method is used in Non Destructive Testing widely.In this dissertation, Electronic Speckle-shearing Interferometry (ESSPI) and the phase-shifting technique are detailedly discussed. The main contents are described as the following:In this dissertation,the measurement and phase-shift of ESSPI are detailedly discussed. The main contents are described as the following:1. The origin, producing method and correlative concept is introduced. A review of development of speckle metrology is presented.Electronic speckle pattern interferometry principle and phase measurement technology in the speckle interferes is introduced2. A review of development of the shape measurement. Several shape measurement methods are introduced ,especially is the combination of digital shadow moirémethod and FTM.3. Electronic speckle-shearing pattern interferometry has been discussed based on the Wollaston prism. this new shearing component shearing principle has been also introduced based on the square prism. 4. principle and changes method of phase-shifting has been introduced. the corresponding changes methods of phase-shifting were carried out a contrast. when the system has been added phase-shifting, the error existing in possibility were discussed. When every step error is simultaneous, the results in contrast is given for three steps and four steps and five steps.