Variable bandwidth optical filters with vertical micromirrors and silicon optical bench alignment technology

This paper reports on a variable-bandwidth optical filter employing a free-space grating as a dispersive element, and a variable-aperture MEMS reflector that selects the passband. This design introduces negligible dispersion across the passband, and provides individual control of the center wavelength and the optical bandwidth, as required for optimization of high-speed optical communication systems. The variable-aperture MEMS reflectors are defined on the vertical sidewalls of silicon-on-insulator material to allow combination with silicon-optical-bench features for integration of fibers, lenses, and gratings.