Dual-parameter optical fiber sensor using FFT amplitude demodulation in animal husbandry

With the development of animal husbandry, modern animal husbandry puts forward higher requirements for the site environment. It is necessary to develop a set of low-cost, reusable, and networked environmental monitoring systems to ensure the healthy growth of livestock and poultry. This study proposes a dual-parameter optical fiber sensor composed of a single-mode fiber cavity and an air cavity using fast Fourier transform amplitude demodulation. The sensor is fabricated by corrosion and fusion, and the refractive index and temperature are investigated experimentally. The double-amplitude demodulation after fast Fourier transform is presented, and different amplitude peaks with different cavities are selected. The sensitivity coefficient matrix is used to measure the refractive index and temperature simultaneously, which avoids the error of inaccurate measurement due to changes in the ambient temperature. This sensor can realize multiplexing of sensors by using a wavelength division multiplexing system, and it is more suitable for the monitoring of animal husbandry networking.