DWDM variable attenuator and multiple-channel power equalizer using MEMS technology

Abstract

This paper reports the design, modeling, fabrication and testing of a novel variable optical attenuator for multi-channel power equalizers to be used in dense wavelength division multiplexed (DWDM) systems. The attenuator is fabricated by silicon surface micromachining technology and is then manually assembled and integrated with two single mode optical fibers that act as optical input and output. A 40 × 40 μm2 mirror coated with gold is driven by a proprietary drawbridge structure to cut partially into the light path between two fibers, enabling the attenuation. The attenuator has a dimension of 0.6 × 1 mm2 excluding the fibers. It has 1.5 dB insertion loss and 45 dB attenuation range, and requires only 8 V driving voltage, showing that it is promising for DWDM applications. Optical and mechanical models of the attenuator have also been established. Although the models are developed with the initial intention of modeling the MEMS attenuator, they are also available to the other types of devices in which the preconditions of the models are satisfied.