Abstract
We propose a technique for calculating the color separation gratings aimed at separating plane light beams of different wavelengths into different diffraction orders. The technique is based on a special-type optimization criterion. With this criterion, the problem of calculating the piecewise-constant grating profile is reduced to sequentially solving independent problems of optimization of the step heights. We derived an analytical expression for the profile of a color separation grating that generalizes the familiar analytical solutions. The criterion introduced is used to design a diffractive optical element (DOE) that generates required light beams when it is illuminated by different wavelengths. Design of color separation gratings able to separate three and five different wavelengths and DOEs to demultiplex and focus the two- and three-wavelength beams is presented.
Acknowledgments
On the Russian part the work is financially supported by the joint Russian-American program ‘Basic Research and Higher Education’ (BRHE), by the presidential grants of the Russian Federation MD-210.2003.01, NS-1007.2003.01, by the RFBR grant No. 04-01-96517 and project FIRB code RBNE01BSXF.