Micromachining of an in-fiber extrinsic fabry-perot interfereometric (MEFPI) sensor by using a femtosecond laser

This paper reports a novel micro extrinsic fiber-optic F-P interferometric (MEFPI) sensor micromachined on a conventional optical fiber (Corning SMF-28) by using a near-infrared femtosecond laser, for the first time to the best of our knowledge. The strain and temperature characteristics of such a sensor were investigated and the experimental results show that the strain and temperature sensitivities are 0.006nm/με and -0.0017nm/°C, respectively. This type of MEFPI sensors has a number of advantages when compared with conventional EFPI sensors, such as easy fabrication, high integration degree, good reliability, low temperature cross-sensitivity, low cost, and capability for mass-production, offering great potential for a wide range of sensing applications.