A Fabry-Perot microinterferometer for visible wavelengths

The authors report on their efforts to develop a silicon-based microinterferometer for optical applications in the visible spectral region using micromachining fabrication techniques. The interferometer is formed by two parallel dielectric mirrors supported on membranes which are electrostatically deflected for wavelength control. A simplified two-wafer fabrication process was designed and investigated. They obtained 250 nm membrane deflection for an applied voltage of 100 V. Hafnium dioxide-silicon dioxide dielectric mirrors with high reflectivity and low stress were fabricated on membrane supports and also free-standing. Anticipated applications include microinstrument spectroscopy systems for atomic absorption, ellipsometry, imaging, optical fiber communications, and general spectrophotometer uses as well as accelerometry.<
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