MEMS Spatial Light Modulator for Spectral Phase and Amplitude Modulation

Thesis Type:

MSc thesis


A diffractive Micro-Electro-Mechanical-system (MEMS) modulator is developed for modulating spectral components of incident light within the optical communication band. This diffractive MEMS spatial light modulator (SLM) is to be used for independently applying amplitude attenuation and phase control along one dimension. This enables a variety of applications for MEMS SLM devices such as channel selective attenuation, pulse shaping, chromatic dispersion compensation and more. The fabrication took place at Sandia National Laboratories where a predefined SUMMiT V process for MEMS designs exists. Furthermore, this fabrication process imposes constraints layer thicknesses. In addition two other constraints govern the design: the available voltage range (0-160 volts), and the need for the smallest mirror possible, due to the need of high resolution, were key factors in the design of the device. The electromechanical behavior of the device was well predicted using analytic calculation and FEA simulations. This thesis describes electrostatic technique and mechanical design features for realizing planar vertical travel in an electrostatically actuated diffractive optical device, which is robust, both to manufacture, and against pull-in. This device consists of many square elements, each 36 micron on a side. These elements act as reflective mirrors spanning a 2D rectilinear space with high fill factor. The mirrors can travel up to about 1.2 microns in the out-of-plane direction for applied voltage of 130 volts. The eigenfrequency of the device is about 24KHz.

Publisher's Version

Last updated on 09/16/2016