Development and characterization of electromagnetic micro shutter in MEMS variable optical attenuator

For Dynamic Power Equalization in all optical networks, a magnetically actuated, surface micromachined micro shutter in variable optical attenuator (VOA) has been fabricated and characterized. The fabrication of the micro shutter is based on the nonsilicon surface micromachine technology. The electroplated FeNi are used as the structure layer, the photoresist and Cu is adopted as the sacrificial layer. In addition, the theoretical analysis of the diffraction optical propagation through the micro shutter in the VOA has also been carried out. The analysis is based on a gaussian beam approximation to the fiber mode, a calculation of the free space diffraction past a square aperture based on the Fresnel-Kirkhoff diffraction integral, and the mode-overlap integral between the diffracted beam and the fiber mode. The theoretical calculation result is in good agreement with the experimental data. Based on the model set up, the performance of the VOA can be optimized for better adjustment characteristics.