Zero-dispersion boundary study of microstructure arrays illuminated by a broadband light source

Abstract

Based on the design requirement of broadband micro-optical elements in diffraction dispersion, such as the integrated guide plate, a theoretical model of microstructure arrays with a broadband light source is established in this paper. The dispersion characteristic regularity of the diffraction spectrum is studied. Dispersion parameter C and its formula are proposed in this paper which can mainly measure the chromatic dispersion degree of the diffraction spectrum. Furthermore, the boundary criterion point of zero-dispersion is given explicitly. The spectrum dispersion regularity, analyzed from the test results in the fabricated rectangular phase grating, is in accord with the theoretical analyses. The consistency verifies the correctness of dispersion parameter C, its formula and the zero-dispersion boundary criterion point. Finally, by applying the dispersion parameter C and zero-dispersion boundary criterion point presented in this paper, that provides guidance for analysis on the dispersion characteristics when the broadband diffractive micro-optical element is designed, we successfully fabricate a white zero-dispersion Fresnel lens sample and a rainbow dispersive Fresnel lens one.