Micromachined diffractive pressure sensor system

摘要

An improved optical pressure sensor determines the pressure of the fluid to be monitored by the deflection of a diaphragm in the pressure chamber of the sensor which has an inlet from the measured vessel. The deflection of the diaphragm is determined by monitoring the interference of diode light reflected from the diaphragm and a silicon grating structure superimposed over the diaphragm, at critical positions. Intensity detectors are placed at critical positions such as the specific orders of the diffraction grating to measure the interference intensity of the reflected light. The interferometric accuracy with which the pressure measurement is made with the present invention far exceeds that obtained with optical pressure sensors described in the prior art.