Open Journal of Applied Sciences, 2016, 6, 373-379 Published Online July 2016 in SciRes. http://www.scirp.org/journal/ojapps http://dx.doi.org/10.4236/ojapps.2016.67038 Nonlinear Optical Spatial Filtering for Medical Image Processing Deyari Henari 1 , Fryad Z. Henari 2 1 Bahrain Defense Force Hospital, Riffa, Kingdom of Bahrain 2 Department of Medical Sciences, Royal College of Surgeons in Ireland, Medical University of Bahrain, Busaiteen, Kingdom of Bahrain Received 7 June 2016; accepted 9 July 2016; published 12 July 2016 Copyright © 2016 by authors and Scientific Research Publishing Inc. This work is licensed under the Creative Commons Attribution International License (CC BY). http://creativecommons.org/licenses/by/4.0/ Abstract The nonlinear properties of Tris(acetylacetonato) Manganese(III) are used to manipulate the spa- tial frequencies at the Fourier plane using 4f-z scan. The technique is a simple self-adaptive all- optical system, which performs image processing and nonlinear optical measurements at the same time. Preferred spatial frequencies can be selected by shifting the nonlinear sample through the focus. Edge enhancement was demonstrated by filtering of low frequency with the nonlinear material at the Fourier plane. Keywords Optical Nonlinearities, 4f-Z Scan, Fourier Optics, Optical Imaging 1. Introduction The Z scan technique [1] has been widely used for characterization of materials exhibiting nonlinear optical ef- fects. These effects are of great technological importance for use in future applications within electronic and photonic devices phase contrast, imaging and spatial filtering [2]-[6]. An example of interest that has attracted a lot of attention, is the light-induced optical property changes which are separated into light-induced absorption changes and light-induced refractive index changes: The light-induced absorption changes are commonly de- scribed by α = α o + βI, where α o is linear absorption coefficient, I is the intensity of the light and β is a nonlinear absorption coefficient. This coefficient contains interesting nonlinear optical effects such as: reverse saturation absorption (RSA), two photon absorption (TPA), and saturation absorption (SA). Both RSA and TPA have been well studied for optoelectronic and photonic devices [2] [3], optical power limiting [4], phase contrast imaging, and phase filtering [5]-[7]. The light-induced refractive index changes are described by the relationship n = n o + How to cite this paper: Henari, D. and Henari, F.Z. (2016) Nonlinear Optical Spatial Filtering for Medical Image Processing. Open Journal of Applied Sciences, 6, 373-379. http://dx.doi.org/10.4236/ojapps.2016.67038