The underlying optical mechanism of the Electronic Speckle Pattern
Interferometer (ESPI) was studied. It was theoretically found that
the previous design concept of conjugacy was not needed and that an
alternative design gives better quality results. This was shown
experimentally using different geometries and point-of-origin for the
reference beam. The intrinsic problem of aliasing in the electronic
apparatus of ESPI was investigated with the aid of an interferometric
technique. Relevant parameters to the system were brought together to
study a simplified model for the distribution of spatial frequencies
at the plane of the object image. Experimentation on photographic
speckle pattern interferometry revealed the need for the introduction
of a variable spatial filter into the ESPI electronic system that
will give way to fringes of holographic quality. Implications for
future designs of ESPI are discussed.
A Doctoral Thesis. Submitted in partial fulfilment of the requirements for the award of Doctor of Philosophy at Loughborough University.
British Council. Mexico, CONACYT (National Council for Science and Technology).