Optical Filter Based on a Spatially Patterned Kinoform Diffractive Lens

We demonstrate a compact all-diffractive setup for spectral synthesis. The system is composed of a circularly symmetric mask attached to a kinoform diffractive lens. Following diffraction-based analysis, a Fourier transform relation between the spatial mask function expressed in the squared radial coordinate and the axial spectral response of the system is found. Experimental results for slicing the initial spectrum in a few channels by using binary masks are in agreement with the theoretical predictions.