Three-dimensional optical Fourier transform and correlation

Three-dimensional optical Fourier transform and correlation.

Optical implementation of a three-dimensional (3-D) Fourier transform is proposed and demonstrated. A spatial 3-D object, as seen from the paraxial zone, is transformed to the 3-D spatial frequency space. Based on the new procedure, a 3-D joint transform correlator is described that is capable of recognizing targets in the 3-D space.

Optical quasi-three-dimensional correlation

A novel optical correlator for three-dimensional (3-D) object recognition is proposed herein. Several projections of a 3-D scene are recorded under white light illumination and fused into a single complex two-dimensional function. After properly filtering this function, it is then coded into a computer-generated hologram (CGH). When the CGH is coherently illuminated, a correlation space between...

Three-dimensional electro-optical correlation

Electro-optical implementation of a three-dimensional (3-D) spatial correlation is proposed. A 3-D scene of objects, seen from the paraxial zone, is correlated with a reference object. As an example of application, we describe a 3-D joint transform correlator that is capable of recognizing targets in the 3-D space. © 1998 Optical Society of America [S0740-3232(98)02102-4] OCIS codes: 070.2590, ...

Optical correlation based on the fractional Fourier transform.

Some properties of optical correlation based on the fractional Fourier transform are analyzed. For a particular set of fractional orders, a filter is obtained that becomes insensitive to scale variations of the object. An optical configuration is also proposed to carry out the fractional correlation in a flexible way, and some experimental results are shown.

Optical Two-Dimensional Fourier Transform Spectroscopy of Semiconductors