A WDM Capable Integrated Optical Readout of a MEMS Sensor

We present experimental validation of an integrated readout technique for interrogating the suspension height of micro-electro-mechanical systems (MEMS) structures using a doubly clamped beam as the demonstration structure. This readout technique is envisaged to be useful in applications such as MEMS-based chemical sensing, where it is necessary to obtain the accurate position of a MEMS beam. The approach is based on the suspended MEMS structure modulating light transmission in an underlying optical waveguide via Fabry-Perrot phenomena. Our experimental results show that changing the doubly clamped beam suspension height by 100 nm can result in an up to 20 dB change in optical power transmitted through an underlying optical waveguide.