In-plane all-photonic transduction with differential splitter using double-step rib waveguide for photonic microcantilever arrays.

We report a differential splitter consisting of an asymmetric double-step multimode rib waveguide and a Y-branch splitter for in-plane photonic transduction of photonic microcantilever deflection. Arrays of photonic microcantilevers are integrated with differential splitters and an optical waveguide network to demonstrate uniformity and sensitivity of transduction. Measurement results from multiple arrays indicate a sensitivity of 0.32x10(-3) nm(-1) and minimum detectable deflection of 141 pm for a 3.5 Hz measurement bandwidth.