Micro mirrors are important for applications like barcode reading, scanning image projection and optical data transfer. Different designs and prototypes of such micro mirrors have been developed and fabricated in bulk micromachining and silicon-on-insulator technology. A large variety of active mirror areas with low roughness and a very flat surface, as well as high reflectivity were achieved. Most applications require dynamic deflection and work at resonance frequencies.
MEMS fabrication technologies cause tolerances in device dimensions and consequently on key parameters like the resonant frequency. Frequency trimming of MEMS devices is a promising approach to overcome these manufacturing tolerances, to tune sensors and actuators for certain operating conditions and it promises an increasing yield in MEMS technology.
In cooperation with 3D micromac AG laser trimming of micro mirrors has been developed.