Coupled U-shaped cantilever actuators for 1 x 4 and 2 x 2 optical fibre switches

Thermally-driven coupled cantilever actuators for multistable switching in micromechanical 1 x 4 and 2 x 2 optical fibre switches are presented. The c oupled U-shaped cantilevers for a lateral movement of fibres eliminate angu lar displacements. The clamp mechanism for multistable switching makes use of an H-shaped buckling platform and results in latching type switches. The coupled U-shaped actuators are thermally-driven with a power of approximat ely 350 mW and 1 W for the 2 x 2 switch and the two outer fibres of the 1 x 4 switch, respectively. The power needed for the two inner fibres of the 1 x 4 switch corresponds to the 2 x 2 switch behaviour. A switching time of 300 ms has been achieved so far. The first fabricated micromechanical 2 x 2 and 1 x 4 switches show good optical properties with insertion losses less than or equal to 1 dB and a crosstalk less than -60 dB. The fabrication is based on full-water micromachining using V-grooves both for fibre alignmen t and for cantilever formation in {100} silicon.