A silicon pressure sensor with an interferometric optical readout

Experiments on a novel miniature pressure sensor based on a silicon micromembrane and a nonelectric contactless readout of its deflection by low-cost integrated interferometric optical means have been performed. In contrast to the well-known piezoresistive or capacitive readout, the contactless optical approach will prove accurate measurements of absolute or differential pressure also in severe environments and at elevated temperatures. The sensors is unusual in the sense that it has two electric output signals which are extremely nonlinear. On a microprocessor, however, with a simple transformation these two outputs can be reduced to a single quite linear response. The sensor is expected to have potential applications in severe environments or elevated temperatures. Various samples of such optical pressure sensors have been built and tested, and preliminary experiments are described.<>