ABSTRACT
For some time now, there has been a strong interest in exploring the capabilities of optics for computing.
The field of optical computing, in general, started in the early sixties with the advent of the laser. At that
time, optical computing was mainly synonymous with analog optical signal processing. Analog optical
signal processing is based on the ability of a lens to perform a two-dimensional Fourier transformation
(Goodman, 1996). This basic operation can be extended to implement optical convolutions and
correlations that can be useful for the processing of radar signals or pattern recognition (van der
Lugt, 1964). This field has been brought near perfection during the past three decades by an
improvement of the algorithms and the hardware, such as temporal and spatial light modulators.
Overviews of the area of analog optical computing were given, for example, by Lee (1981); Casasent
(1997). Recently, analog computing has seen renewed interest in the context of information security
(Javidi, 2005).
