title: Temperature sensing in seawater based on microfiber knot resonator.
abstract: Ocean internal-wave phenomena occur with the variation in seawater vertical temperature, and most internal-wave detections are dependent on the measurement of seawater vertical temperature. A seawater temperature sensor based on a microfiber knot resonator (MKR) is designed theoretically and demonstrated experimentally in this paper. Especially, the dependences of sensing sensitivity on fiber diameter and probing wavelength are studied. Calculated results show that sensing sensitivity increases with the increasing microfiber diameter with the range of 2.30-3.91 μm and increases with the increasing probing wavelength, which reach good agreement with results obtained by experiments. By choosing the appropriate parameters, the maximum sensitivity measured can reach to be 22.81 pm/°C. The seawater temperature sensor demonstrated here shows advantages of small size, high sensitivity, easy fabrication, and easy integration with fiber systems, which may offer a new optical method to detect temperature of seawater or ocean internal-wave phenomenon and offer valuable reference for assembling micro sensors used for other parameters related to seawater, such as salinity, refractive index, concentration of NO3- and so on.
authors.affiliation: Department of Physics, College of Information Science and Engineering, Ocean University of China, Qingdao 266100, China. yanghongjuan1989@gmail.com.
authors.forename: Hongjuan
authors.initials: H
authors.lastname: Yang
authors.affiliation: Department of Physics, College of Information Science and Engineering, Ocean University of China, Qingdao 266100, China. wangshanshan@ouc.edu.cn.
authors.forename: Shanshan
authors.initials: S
authors.lastname: Wang
authors.affiliation: Department of Physics, College of Information Science and Engineering, Ocean University of China, Qingdao 266100, China. wxinflying@foxmail.com.
authors.forename: Xin
authors.initials: X
authors.lastname: Wang
authors.affiliation: Department of Physics, College of Information Science and Engineering, Ocean University of China, Qingdao 266100, China. wjing@ouc.edu.cn.
authors.forename: Jing
authors.initials: J
authors.lastname: Wang
authors.affiliation: Department of Physics, College of Information Science and Engineering, Ocean University of China, Qingdao 266100, China. oucliaoyipeng@hotmail.com.
authors.forename: Yipeng
authors.initials: Y
authors.lastname: Liao
mesh_terms: D004867:Equipment Design; D005336:Fiber Optic Technology; D007368:Interferometry; D009792:Oceans and Seas; D012031:Refractometry; D012623:Seawater / Q000737:chemistry*; D013696:Temperature