<title>Electronic speckle pattern interferometry with holo-optical element</title>

Electronic Speckle Pattern Interferometry techniques for non-destructive evaluation: a review

“…The light intensity recorded in the image plane is a function of the reference and object wave fronts and can be expressed as (59) : where, IA is the intensity distribution of the object in its initial state and φ is the phase difference between the waves.…”

Application of ESPI for the NDE of low-modulus materials using mechanical loading

“…Optical holography and Electronic Speckle Pattern Interferometry (ESPI) are emerging Non-Destructive Evaluation (NDE) methods which can be applied for the detection and measurement of displacement, strain, vibration, flow analysis, etc [1][2][3][4][5][6][7] . Because of the non-contact nature, these methods can be used for the detection of defects even in cryogenic conditions and corrosive environments.…”