Temperature, stress, refractive index and humidity multi parameter highly integrated optical fiber sensor

Multi parameter measurement based on optical fiber sensor has been a research hotspot in recent years. In this work, four kinds of optical fiber sensors, LPFG, FBG, PMF and SMS are used. The transmission characteristics and sensing characteristics of each sensor are analyzed in detail. Based on the modulation of resonance wavelength by environmental variables, the accurate and synchronous real-time detection of temperature, stress, refractive index and humidity is realized. We use all-optical coupling cascade and wavelength division multiplexing (WDM) technology to prepare a highly integrated sensing device. The problem of signal crosstalk of each sensor is solved, and the cost of signal transmission and reception is greatly reduced. It is of great significance for monitoring a variety of environmental variables under extreme conditions.