Low-Loss Fiber-Optic Intrinsic Fabry-Perot Micro-Cavity Interferometric Sensor

In this paper, an intrinsic fiber-optic Fabry-Perot (F-P) micro-cavity interferometer sensor fabricated by femto-second laser micro-machining technology is proposed and demonstrated experimentally. The insertion loss of the sensor head was measured under different laser writing conditions. And reflection characteristics of both single F-P micro-cavity interferometer and cascade F-P micro-cavity interferometer are studied with temperature change. Results show that femto-second laser induced intrinsic fiber micro-cavity as low-coherence F-P interferometer temperature sensor has the properties such as low insertion loss, low cost and good multiplex capability.