A micro Fabry-Perot interferometer (M-FPI) is constructed by splicing a short section of polarization-maintaining photonic crystal fiber (PM-PCF) to an end-cleaved single-mode fiber with controllable offset. Due to the high effective optical path difference induced by the solid core of the PCF, the M-FPI has an ultrasmall cavity of approximately 110 μm. The temperature sensitivity within a range from 33 °C to approximately 600 °C is measured to be 13.8 pm/°C, which shows good agreement with the theoretical result. This proposed sensor has the advantages of ultracompact size and high stability. Therefore, it is suitable for various space-limited sensing applications in harsh environments.
© 2012 Chinese Optics LettersPDF Article