Nonlinear coherent optical image processing using logarithmic transmittance of bacteriorhodopsin films

Self-adaptive spatial filtering by use of azo chromophores doped in low glass-transition-temperature polymers

We report on self-adaptive spatial filtering by combination of the self-adaptive polarization-rotation property of Disperse Red1-doped polymers with low glass-transition-temperature and Fourier-transform operation. Our system can be operated with only an action beam with object information and without a probe beam for image readout. Edge enhancement by the action beam-probe beam is demonstrated as an example of the system's application to spatial filtering.

Optical Fourier processing using photoinduced dichroism in a bacteriorhodopsin film

The photoinduced dichroism in bacteriorhodopsin films has been investigated in view of its application for optical Fourier processing. A simple optical system for Fourier processing is demonstrated that does not require precise alignment and vibration isolation. The basic principle of operation relies on the intensity dependence of photoinduced dichroism in a bacteriorhodopsin film. Experimental results with Fourier processing are shown for edge enhancement.