Operations achievable with coherent optical information processing systems

Coherent optical information processing systems are well known to be capable of performing a certain limited class of operations, such as Fourier transformation, Fresnel transformation, and linear, space-invariant filtering. Recently, advances have been made in broadening the class of achievable operations to include nonlinear operations and space-variant linear filtering. In this paper we review the operations commonly achieved in the past, and discuss newer techniques which are capable of significantly extending the class of achievable operations.