Measurement of small vibrations using electronic speckle pattern interferometry: Theory

A theoretical analysis of a recently published method for measurement of small vibrations using electronic speckle pattern interferometry is given. From the general description of the signal processing in electronic speckle pattern interferometry, we derive a theory that applies to ideal operation of the system. For two special cases, including the small-amplitude limit, the theory is extended to include nonideal effects. The calculated response functions show good agreement with experimental results also beyond the linear small-amplitude range.