Integrated optical differential pressure transducers achieved using thin buckled silica membranes and direct UV written planar Bragg gratings

Direct UV written differential pressure sensors have been fabricated in a silica-on-silicon platform. The reported components achieve physical sensitivity through actuating planar Bragg gratings defined within a thin (<40 μm) silica membrane. The optimised transducer exploits the condition of static membrane buckling to resolve both positive and negative pressure differentials, either side of the membrane. The fabricated device has demonstrated operation over a 202 kPa range with a 0.36 kPa resolution.