Abstract:
A dynamic optical spectral filter is implemented in a microelectromechanical system (MEMS). It comprises a frame. An array of mirrors is provided on a first portion of the frame, along with a second array of adjustment mirrors on a second portion of the frame. An array of variable beam splitters is provided on a middle portion of the frame, between the first array and the second array. Finally, to provide the filter functionality, optical delays are disposed in beam paths between the first mirror array the second mirror array. These elements are used to produce multiple Mach-Zehnder interferometers, such as cascaded or series interferometers. Implementations have advantages associated with speed of operation and can have polarization isotropy.
Abstract:
Tabs or stops are integrated into a membrane structure to prevent its snapdown. Features comprising two surfaces separated by a distance equal to the maximum desired range of movement are produced. When the two surfaces contact, the motion of the structure is arrested or greatly diminished by increasing its rigidity. For an electrostatically actuated MEMS structure, these features can be used to limit the range of motion such that pull-in or snapdown is avoided, greatly enhancing the reliability of the device. One key design feature is that the two contacting surfaces are maintained at the same electrical potential avoiding problems associated with electrostatic cavity discharge.