title: Roll up polymer/oxide/polymer nanomembranes as a hybrid optical microcavity for humidity sensing.
abstract: A hybrid optical microcavity from rolled-up polymer/oxide/polymer nanomembranes presents its excellent capability for environmental relative humidity detection. When exposed to a moist surrounding, poly(acrylic acid)/poly(ethylenimine) polymers swell greatly due to the absorption of water molecules, which thus leads to an increased wall thickness of the tubular optical microcavity and therefore presents a profound wavelength redshift of its whispering-gallery mode resonance. These experiments fit well with the calculation based on the Mie-scattering theory. Theoretical calculation also demonstrates that the thin walls of our tubular microcavities contribute to a high detection sensitivity compared to other microcavities. Our work could lead to new designs and applications of optical microcavities.
authors.affiliation: Department of Light Sources and Illuminating Engineering, Engineering Research Center of Advanced Lighting Technology, Ministry of Education, School of Information Science & Technology, Fudan University, Shanghai 200433, People's Republic of China. cuixugao@fudan.edu.cn.
authors.forename: J
authors.initials: J
authors.lastname: Zhang
authors.forename: J
authors.initials: J
authors.lastname: Zhong
authors.forename: Y F
authors.initials: YF
authors.lastname: Fang
authors.forename: J
authors.initials: J
authors.lastname: Wang
authors.forename: G S
authors.initials: GS
authors.lastname: Huang
authors.forename: X G
authors.initials: XG
authors.lastname: Cui
authors.forename: Y F
authors.initials: YF
authors.lastname: Mei