Micromirror arrays are commonly found in digital projectors. However, they can be utilized for other applications. For example, in a past project for Geospatial Systems, Inc. (GSI, now Optech), ASE creatively used an off-the-shelf projector array in the construction of a multi-object spectrometer. The array is used for target selection in place of a conventional slit mask or fiber bundle. It allows the system to be rapidly reconfigured and makes it well suited for studying objects that cover a small field of view, such as star clusters.

A recent article in “MEMS Investor Journal” describes another interesting application, a variable focal length lens to improve the zoom performance of cell phone cameras. Currently, camera phones do not contain moving lens elements to vary the focal length like a regular zoom lens. Instead, images are zoomed digitally, which results in lower image quality compared to optical zoom. Micromirrors placed in concentric circles within a plane can be used to produce optical zoom. The tilt of the mirrors is different from circle to circle such that light is focused to a single point. The tilt angles can be adjusted to vary the focal length, which provides the same effect as moving lens elements. The researchers have designed a system that would deliver 3.5x optical zoom. They plan to build prototypes this year.

Consumers would certainly appreciate improved zoom capabilities in camera phones and it would add to the ever-expanding list of features for these handheld devices. Perhaps the need for stand-alone point-and-shoot digital cameras will someday be eliminated.