Extrinsic Fabry Perot interferometer fiber sensor for simultaneous measurement of hydrazine vapor and temperature

摘要： A novel optical fiber sensor of hydrazine (N2H4) vapor and temperature is proposed and demonstrated. The perylene diimide derivative (TClPDI) is deposited on the enlarged optical fiber end face as sensitive film, and an extrinsic Fabry Perot resonator is formed with fiber bragg grating (FBG) and fiber end face. The film device exhibits high sensitivity and reproducibility to hydrazine vapor with liner concentration dependent characteristic, which owes to the change of refractive index under hydrazine vapor. The enhancement sensitivity and temperature monitoring could be obtained due to the FBG. The results show that a hydrazine vapor sensitivity of 0.01 dB m/ppm, a temperature sensitivity of 9.8 pm/?C could be achieved. In addition, the effect of enlarged fiber end face on the form of TClPDI film was investigated, the sensing mechanism of the film device to hydrazine vapor was studied. The sensor has the advantages of all optical system, tiny, high repeatability, high reliability and two parameters sensing, showing high potential for practical application.