Quasi-Distributed Dual-Parameter Optical Fiber Sensor Based on Cascaded Microfiber Fabry–Perot Interferometers

Abstract

We propose and demonstrate a quasi-distributed fiber sensor based on cascaded microfiber Fabry-Perot interferometers (MFPIs) for simultaneous refractive index (RI) and temperature measurement. By employing MFPI that is fabricated by taper-drawing the center of a uniform fiber Bragg grating on standard fiber into a section of microfiber, dual-parameters including RI and temperature can be detected through demodulating envelop and resonant wavelength of the reflection spectrum of the MFPI. Then, wavelength-division-multiplexing is applied to realize quasi-distributed dual-parameter sensing by using cascaded MFPIs with different Bragg wavelengths. A prototype sensor system with five cascaded MFPIs is constructed to experimentally demonstrate the sensing performance. The quasi-distributed dual-parameter sensing system has great significance on monitoring gradient parameter-variations in chemical and biological sensing applications.

Keywords

• Optical sensors
• remote sensing
• temperature measurement
• refractive index
• and microstructure