Through exploiting a modified focal-length function, two-dimensional metallic cylindrical focusing micromirrors (MCFMs) with different preset focal depths are designed. Rigorous electromagnetic theory and the boundary element method are applied to analyzing the focal characteristics, including the actual focal depth, the relative focal depth, the focal spot size and the diffraction efficiency. Through setting the preset focal depth to be positive or negative, numerical results reveal that the designed MCFMs can successfully modulate the optical field distribution to achieve a long axial focal depth or increased lateral resolution, respectively. In addition, due to the inherent achromatic aberration property of the metallic reflective system, the common long-focal-depth region of the designed MCFM under multiwavelength illumination is greatly enlarged, in comparison with a dielectrically cylindrical microlens. It is expected that the designed MCFMs should have many practical applications in micro optics systems.

Date Published: 15 November 2011
PDF: 6 pages
Proc. SPIE 8321, Seventh International Symposium on Precision Engineering Measurements and Instrumentation, 83210U (15 November 2011); doi: 10.1117/12.903890

Published in SPIE Proceedings Vol. 8321:
Seventh International Symposium on Precision Engineering Measurements and Instrumentation
Kuang-Chao Fan; Man Song; Rong-Sheng Lu, Editor(s)