Abstract: The present invention discloses a residual pressure measurement system for a MEMS pressure sensor with an F-P cavity and method thereof, the measurement system includes a low-coherence light source, a 3 dB coupler, a MEMS pressure sensor, an air pressure chamber, a thermostat, a pressure control system, a cavity length demodulator, an acquisition card and a computer. The measurement method comprises: performing cavity length measurement by using the reflecting light by the pressure control system at two temperatures, respectively, so as to calibrate the MEMS pressure sensor and establish a relationship between the absolute phase of a monochromatic frequency and the external pressure; performing linear fitting to the two measurement data to obtain all the external pressure when the cavity length of two measurement data are equal to each other, and substituting the theoretical equation for calculation to obtain the residual pressure under the flat condition of the diaphragm.

Abstract: The present invention discloses a residual pressure measurement system for a MEMS pressure sensor with an F-P cavity and method thereof, the measurement system includes a low-coherence light source, a 3 dB coupler, a MEMS pressure sensor, an air pressure chamber, a thermostat, a pressure control system, a cavity length demodulator, an acquisition card and a computer. The measurement method comprises: performing cavity length measurement by using the reflecting light by the pressure control system at two temperatures, respectively, so as to calibrate the MEMS pressure sensor and establish a relationship between the absolute phase of a monochromatic frequency and the external pressure; performing linear fitting to the two measurement data to obtain all the external pressure when the cavity length of two measurement data are equal to each other, and substituting the theoretical equation for calculation to obtain the residual pressure under the flat condition of the diaphragm.

Abstract: The present invention discloses a high-resolution polarized low-coherence interference pressure measurement device and method, which comprise a broadband light source (1), an optical fiber coupler (2), an optical fiber Fabry-Perot sensor (3), a collimating lens (4), a polarizer (5), a birefringence wedge (6) having a spatial dip angle, an analyzer (7), a matrix camera (8), and a signal processing unit (9), which are successively provided from an input end to an output end; wherein light emitted from the broadband light source (1) passes through the optical fiber coupler (2) and arrives at the optical fiber Fabry-Perot sensor (3), and returned light emitted from the optical fiber Fabry-Perot sensor (3) is led into a demodulation interferometer; a change in pressure is transformed into a change in length of a Fabry-Perot cavity by the optical fiber Fabry-Perot sensor (3), and different pressures correspond to different lengths of the Fabry-Perot cavity; the collimating lens (4), the polarizer (5), the birefring