Optical diversity by nanoscale actuation

Miniaturization in free-space optical systems presents a significant challenge because limiting the physical aperture typically degrades resolution. That is, images and spectra become "blurry," and features of interest in them are lost. We have devised a method to resolve this dilemma by exploiting the benefits of micro-actuators with nanometer positioning accuracy. Inspired from the diversity method in radar and satellite communications, "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. In ICIOD, diversity is realized by MEMS actuators that mechanically modify the optical response of a diffraction grating. The individual low-resolution measurements are combined using flavors of the regularized pseudo-inverse method (e.g. Wiener filtering or expectation maximization.) In this paper, we, describe in detail a case study of ICIOD for a potential compact (shirt-button sized) spectrometer and its core component, the analog tunable grating.