Strain sensing based on gourd-shaped optical microresonator

• Published in: Optics and lasers in engineering Vol. 183; p. 108470
• Main Authors: Yang, Hedong, Xie, Chengfeng, Wang, Mengyu, Guo, Zhuang, Wei, Bin, Shi, Jiulin, Zhang, Lei, He, Xingdao
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.12.2024
• Subjects: Fiber optic sensing; Gourd-shaped optical microresonator; Strain sensing; Whispering gallery mode; Strain sensing; Fiber optic sensing; Whispering gallery mode; Gourd-shaped optical microresonator
• ISSN: 0143-8166
• DOI: 10.1016/j.optlaseng.2024.108470

•Proposed a new structure of solid-state fiber-optic microresonator for strain sensing application.•The strain sensitivity of the new structure is about 2.5 times higher than that of the normal two-bottle structure.•The stability and repeatability of the microresonators were experimentally verified. We have fabricated a gourd-shaped optical microresonator (GSOM) with a maximum Q exceeding 107. The resonator consists of a large and a small microsphere cavity. The diameter of the large microsphere cavity is about 185 μm and the diameter of the small microsphere cavity is about 164 μm, and the diameter at the central of the resonator is about 140 μm. Through theoretical and experimental investigations on the structure and strain response characteristics of the GSOM, the mechanical strain characteristics of the GSOM have been accurately measured and the strain sensitivity coupled to the central region of the resonator has been obtained to a maximum value of 4.26pm/με, which is not only simple to fabricate but also higher than that of the strain sensitivity of the solid-state strain microresonator sensors reported previously. In addition to this, experiments have demonstrated high stability and repeatability.