Environmental parameters monitoring using a single mode-bare core multimode-single mode optical fiber sensor

We report a single mode-bare core multimode-single mode (SBMS) optical fiber sensor, for environmental parameters in-situ monitoring. Compared with the reflection structure and the transmission structure of the SBMS optical fiber sensors, we found that the repeatability and stability results of the reflection structure were much better than that of the transmission structure’s. The principle of this experimental design is based on the optical fiber which can be transmitted by the outside temperature modulation. Because the parameters of the light transmitted in the single mode-multimode single mode (SMS) fiber structure are subject to the change of the external physical factors, this type of fiber optic temperature sensor is made by multiple modes of transmission in a multimode fiber. As the light source transmits a distance in the multimode fiber, it will change greatly, making the input light and the final output light produce a great difference. While the length of the bare core multimode fiber was around 8.1cm, the temperature cross-sensitivity of the device had good linearity and was around 0.009075nm/°C , from 50 °C to 350 °C. Furthermore, the increased temperature curve was almost coincided with the decreased temperature curve.