Innovative Fourier Optics
Supervisor: [ Dr. Ilia P. Nikolaev ]

Image of the US Air Force Resolution Target, differentiated along the horizontal direction by means of a Fourier filter.


General layout of an optical Fourier processor for shadow mask inspection.

Fourier optics is one of the most elegant branches of classical optics. Using a Fourier filter, one can selectively affect the transverse structure of a laser beam, redistributing its intensity and/or phase. Most important results concerning this general idea were obtained in 50s-70s of the past century. Nevertheless, the pioneers of Fourier optics kindly left some minor problems to be solved by their disciples.

Starting our experiments with both phase and amplitude Fourier filters, we developed some new methods for visualizing the phase distribution of a light beam and for optically performing some image processing operations, such as differentiation. Afterwards, we applied these ideas to nonlinear optical systems with distributed feedback and suggested some new methods for controlling the properties of optical patterns generated by such systems.

In 1999 we had a Cooperation Agreement with LG Electronics (South Korea), which concerned the development of concepts of Fourier optics-based inspection of shadow masks for CRT monitors. The abstract of our final report can be found [ here ].

Selected publications:

• Larichev A.V., Nikolaev I.P., Costamagna S., and Violino P., Advanced phase knife technique, Opt. Comm. 121 (1995) 95.
• Nikolaev I.P., Larichev A.V., Shmal'gauzen V.I., Controlled optical structures in a nonlinear system involving the suppression of low spatial frequencies in the feedback loop, Quantum Electron. 30 (2000) 617.
• Nesterouk K.S., Nikolaev I.P., and Larichev A.V., Image differentiation with the aid of a phase knife, Optics and Spectroscopy 91 (2001) 295.
• Nikolaev I.P., Spatial filtering as a method for controlling the structure of an optical radiation field, J. of Opt. Technology 69 (2002) 54.