An optical liquid level sensor based on core-offset fusion splicing method using polarization-maintaining fiber

5th International Conference on Advances in Optoelectronics and Micro/Nano-optics

Lou, Weimin^1 ; Chen, Debao^1 ; Shen, Changyu^1 ; Lu, Yanfang^1 ; Liu, Huanan^1 ; Wei, Jian^1

Institute of Optoelectronic Technology, China Jiliang University, Hangzhou, China^1

关键词: Cladding modes;    Effective refractive index;    Fiber structures;    Fusion splicing;    Optical liquids;    Optical path difference;    Power intensity;    Wavelength shift;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/680/1/012018/pdf
DOI  :  10.1088/1742-6596/680/1/012018

来源: IOP

【 摘 要 】

A simple liquid level sensor using a small piece of hydrofluoric acid (HF) etched polarization maintaining fiber (PMF), with SMF-PMF-SMF fiber structure based on Mach- Zehnder interference (MZI) mechanism is proposed. The core-offset fusion splicing method induced cladding modes interfere with the core mode. Moreover, the changing liquid level would influence the optical path difference of the MZI since the effective refractive indices of the air and the liquid is different. Both the variations of the wavelength shifts and power intensity attenuation corresponding to the liquid level can be obtained with a sensitivity of 0.4956nm/mm and 0.2204dB/mm, respectively.