Miniature fiber optic pressure sensor based on Fabry-Perot (F-P) interferometric principle is described. A piece of hollow fiber with 175 μm out diameter is fused directly onto a fiber tip to form an air gap for the F-P cavity. The essential pressure sensing element is a thin diaphragm which is fused onto the other end of the hollow fiber. First

an entire quartz structure miniature fiber optic pressure sensor is fabricated by cleaving

fused splicing and etching. The pressure response of the sensor has been tested

showing a sensitivity of 41.09nm/MPa in the full pressure scale of 0-3.1MPa. The system resolution of 681Pa has been reached for the pressure measurement. The temperature sensitivity of the sensor has also been tested under atmospheric pressure

exhibiting a weak temperature dependence of 1.07KPa/℃ in the test temperature range from 20 to140℃. Since it is hard to further decrease the thickness of the quartzose diaphragm，A polymer（PSQ） diaphragm is used instead to increase the sensitivity of the sensor. The pressure response of the PSQ diaphragm based sensor has also been tested under room temperature

showing a sensitivity of 1 886.85nm/MPa

in the full pressure scale of 0.1-2.1MPa

with a system resolution of 53Pa.