Rigorous electromagnetic analysis of a dual-metallic-cylindrical-focusing- micromirror array with long focal depth

摘要

A dual-metallic-cylindrical-focusing-micromirror array (DFMA) with long focal depth (LFD) is designed, and the focusing properties are investigated. Rigorous electromagnetic theory and the boundary element method are employed in our analysis. Many focusing properties, such as the actual focal depth and relative focal depth on the axial plane, together with the focal spot size and diffraction efficiency on the real focal plane are characterized. For TE incident polarization, simulation results reveal that the designed LFD DFMA can exhibit LFD functions. Through comparison with the LFD single-metallic-focusing- micromirror (SFM), interference effect in the LFD DFMA is disclosed. When the preset focal depth of the LFD DFMA is increased, the interference effect between the dual micromirrors is enhanced, which makes the LFD DFMA behave differently from the LFD SFM.