EURASIP Journal on Applied Signal Processing 
Volume 2005 (2005), Issue 10, Pages 1498-1519
doi:10.1155/ASP.2005.1498

Fractional Transforms in Optical Information Processing

Tatiana Alieva,1 Martin J. Bastiaans,2 and Maria Luisa Calvo1

1Facultad de Ciencias Físicas, Universidad Complutense de Madrid, Ciudad Universitaria, Madrid 28040, Spain
2Faculteit Elektrotechniek, Technische Universiteit Eindhoven, Postbus 513, Eindhoven 5600 MB, The Netherlands

Received 31 March 2004

Abstract

We review the progress achieved in optical information processing during the last decade by applying fractional linear integral transforms. The fractional Fourier transform and its applications for phase retrieval, beam characterization, space-variant pattern recognition, adaptive filter design, encryption, watermarking, and so forth is discussed in detail. A general algorithm for the fractionalization of linear cyclic integral transforms is introduced and it is shown that they can be fractionalized in an infinite number of ways. Basic properties of fractional cyclic transforms are considered. The implementation of some fractional transforms in optics, such as fractional Hankel, sine, cosine, Hartley, and Hilbert transforms, is discussed. New horizons of the application of fractional transforms for optical information processing are underlined.