Optical and mechanical performance of a novel magnetically actuated MEMS-based optical switch

Abstract

A novel magnetically actuated 8 8-port MEMSbased fiber-optic switch is described. Fiber-to-fiber insertion loss measurements of six 8 8 switch units show average and worst-case insertion loss of 1.3 dB and 2 dB, respectively. Low insertion loss is achieved through a unique MEMS design that uses anisotropically etched single-crystal silicon sidewalls to provide a global mechanical alignment stop for an array of MEMS mirrors. This alignment surface produces a uniform and repeatable mirror angle across the mirror array. Mirror misalignment is attributed to the surface roughness of the silicon sidewalls. Repeated interferometric measurements of the mirrors of 24 8 8 switch units show repeatability of the mirror angle of 3 10 3 degrees, while the uniformity of the mirror angle across the MEMS array is2 10 2 degrees, in agreement with the angular error predicted from measurements of sidewall surface roughness. In turn, the average repeatability and uniformity of the insertion loss are 0.01 dB and 1 dB, respectively, in agreement with predictions based on the interferometric measurements. Finally, the unique dynamics of the magnetic actuation and electrostatic addressing scheme are described. Measurements show that fast switching can be achieved by driving the mirrors with a magnetic pulse that is faster than the mechanical resonant frequency of the mirror, relying on an electrostatic clamping force to capture the mirror as it overshoots the magnetic field angle. This actuation scheme is shown to result in switching times of 8.5 ms to 13.5 ms, but requires accurate control of the kinetic energy of the mirror.[1169]Index Terms-Microelectromechanical devices, optical fiber devices, optical switches.

Modeling 3D magnetic fields for precision magnetic actuators that use non-periodic magnet arrays

“…X ∼ e ik x x , Y ∼ e ik y y , Z∼ e −k xy z or sinh(k xy z) (17) where k x , k y , and k xy are separation constants related by:…”

“…1b and 2 [11]. Several small-scale devices that use non-periodic arrays include probe-based data storage devices [12][13][14] and optical switches [15][16][17][18].…”

High-performance silicon scanning mirror for laser printing

“…However, for the printer application, the number of coil turns required on the printer scanning mirror was computed to be impractically large, resulting in excessively high resistive power dissipation and a large silicon structure. Another electromagnetic actuation scheme uses the torque generated on a permanent magnet or permeable material attached to the scanning mirror by the variable field generated by an external electromagnet [16,17]. This approach incurs the significant penalty of the attached magnet's inertia oscillating at the scanning frequency.…”

Planar microlens with front-face angle: design, fabrication, and characterization

“…This approach, however, has limited the port count of optical switches. The use of planar waveguides in optical cross-connect architecture [6][7][8][9] has been proposed and implemented to increase port counts and reduce the freespace propagation loss. However, these approaches require relatively complex fabrication processes involving the realization of the waveguide and the MEMS switch in separate substrates, which introduce alignment issues.…”