Bulk-etched surface micromachined and flip-chip integrated micromirror array for infrared applications

The 2-dimensional phase-only micromirror array is a promising microsystem that leads to many applications such as optical beam steering, optical data interconnects, real-time image recognition, optical spectroscopy, and aberration correction. Large deflection of micromirror is required to be able to modulate light in infrared wavelength. In previous works on piston micromirrors, surface micromachining was used to fabricate parallel plate structures with a narrow gap between the mirror and underlying address electrode, that is not adequate to modulate light in longer wavelength than in visible spectrum. In this paper, a novel technique that combines the surface and bulk micromachining was used to implement the infrared micromirror array through a bulk-etched MUMPS surface micromachining.