The invention discloses a
fiber optic temperature sensor based on a sealed micro cavity gas
thermal effect and a manufacturing method of the
fiber optic temperature sensor. A sensor structure comprises a Fabry-Perot micro cavity and an air micro cavity, and the two
micro cavities are partitioned through a thin
silicon membrane. The
atmospheric pressure environments of the two
micro cavities are respectively controlled in the sensor manufacturing process, so that the two
micro cavities have
pressure difference. When the temperature changes, according to an
ideal gas state equation, the
atmospheric pressure inside the two micro cavities is changed, so that a
silicon wafer in the middle of the two micro cavities is deformed because of the change of the
pressure difference. At the same time the inner surface of the
silicon wafer and the reflection surface inside the Fabry-Perot micro cavity form a low-
fineness Fabry-Perot interferometer, the deformation of the membrane is just the
length change of the Fabry-Perot micro cavity, and
temperature measurement is achieved by demodulating the
length change of the cavity. Compared with the prior art, the
temperature sensitivity of the sensor disclosed by the invention can be flexibly controlled by designing the
diameter, the temperature and the
pressure difference of the silicon
wafer, and expected
temperature sensitivity is achieved. In addition, the in-
batch production of the senor is beneficial to cost reduction, and commercialization can be realized.