Scaling laws for MEMS mirror-rotation optical cross connect switches

Abstract

Abstract-The design of large-scale mirror-rotation free-space optical cross-connect switches based on arrays of microelectromechanical torsion mirrors is considered. The layout of a compact switch is first presented. The parameters of the Gaussian beam that maximizes the port count for a given mirror turn angle is then identified, and the supporting optical system needed to create the desired beam is defined. Scaling laws for the optical path length needed for a given number of ports are then derived. Numerical simulations are used to verify the ideal configuration, and scaling laws are proposed for various departures from the ideal. It is shown that ideal operation can still be maintained when the mirrors are curved, and operating conditions that minimize the effect of mirror curvature are identified.

Integrated optical and MEMS based design process for a variable optical attenuator

“…A large ROC of the membrane affects the Gaussian beam parameters less than a small ROC [5]. Static and dynamic curvatures are present in the device membrane.…”

Free-Space Optical MEMS

“…With an increasing number of wavelengths and bandwidth in dense wavelengthdivision-multiplexed (DWDM) networks, there is a need for optical crossconnect (OXC) with a large port count. [14][15][16] The dual-axis analog scanning capability is key for these applications since each mirror associated with the input fiber array can point to any mirror associated with the output fiber array. Implementation of N × N OXC using two arrays of N analog scanners is illustrated in Fig.…”

“…Syms provides a complete discussion of scaling laws for MEMS freespace optical switches. [16] For a large port count (approaching 1000 × 1000), single-crystal micromirror scanners are necessary to achieve a large mirror size with the required flatness. Micromirrors fabricated by standard polysilicon surface-micromachining processes can have significant curvature due to residual stress of the deposited thin films.…”

MEMS optical switch: Switching time reduction

“…was studied in the past and several solutions were proposed [7][8][9][10]. Similarly, the static and dynamic characteristics of individual micro-mirrors were analysed [11][12][13][14][15].…”