Abstract

Miniaturization in free-space optical systems, while desirable for portable sensors and telecommunication equipment, presents a significant challenge because limiting the physical aperture typically degrades resolution. That is, waveforms, images and spectra become “blurry,” and features of interest in them are lost. We have devised a method to resolve this dilemma, inspired from the diversity method in radar. “Integrated computational imaging with optical diversity” or ICIOD (pronounced “Hesiod”), is premised on the fact that resolution improves if a measurement is repeated by several systems with different transfer functions. We have implemented a microspectrometer where ICIOD is realized by mechanical means, using MEMS actuators. The actuation modifies the optical response of a diffraction grating. The individual low-resolution measurements are combined using flavors of the regularized pseudo-inverse method. In this paper, we describe in detail a case study of ICIOD for a compact spectrometer that will eventually be as small as the button of a shirt.

© 2003 Optical Society of America