Interference effect of dual diffractive cylindrical microlenses analyzed by rigorous electromagnetic theory

The interference effect between dual diffractive cylindrical microlenses is investigated based on the boundary-element method. The interference patterns and intensity distributions of the near field and the middle-distance field are presented. The influence of various factors such as the wavelength of illuminating light, the size of the individual microlens, the beam aperture of the incident light, the preset focal length, and the refractive index of microlens material, on the interference results is studied in detail. The results demonstrate that the interference effect is dependent on the spacing between dual microlenses and surface-relief structures. We also indicate how to diminish the interference effect. It is believed that this work will provide useful information for designing diffractive microlens arrays with submicrometer-scale dimensions.