Optical image and data processing with cavity type-II Second Harmonic Generation

We show the possibilities of type-II intracavity Second Harmonic
Generation as a way to perform all-optical parallel processing of
images. To do image processing operations we pump the crystal
at two orthogonal polarizations at fundamental frequency, the
y-polarized pump is an homogeneous wave and the x-polarized pump has
an spatial dependence that represents the image to be processed.
Depending on the relative intensities between the two pumps,
different operations can be done. If the intensity of the
homogeneous pump is greater than the intensity of the x-polarized
pump we obtain at the output of the system the same image but at
second harmonic frequency and in the y-polarization. Also the
inverted image appears in the y-polarization at fundamental
frequency. If the intensity of the homogeneous field is lower than
the x-polarized field in some regions of the image this regions
appear enhanced in the x-polarized fundamental field at the output
of the system, and in the second harmonic we obtain the contour of
the image. Furthermore the system shows noise filtering properties.
We show that injecting two images simultaneously it is possible to
perform logical operations such as \