title: Ringing phenomenon in chaotic microcavity for high-speed ultra-sensitive sensing.
abstract: The ringing phenomenon in whispering-gallery-mode (WGM) microcavities has demonstrated its great potential for highly-sensitive and high-speed sensing. However, traditional symmetric WGM microcavities have suffered from an extremely low coupling efficiency via free-space coupling because the emission of symmetric WGMs is non-directional. Here we report a new approach for high-speed ultra-sensitive sensing using the ringing phenomenon in a chaotic regime. By breaking the rotational symmetry of a WGM microcavity and introducing chaotic behaviors, we show that the ringing phenomenon in chaotic WGM microcavities extends over both the positive and the negative frequency detune, allowing the ringing phenomenon to interact with analytes over a much broader bandwidth with a reduced dead time. Because the coupling of the chaotic microcavity is directional, it produces a significantly higher signal output, which improves its sensitivity without the need of a fiber coupler.
authors.affiliation: Key laboratory of Optical Information Science and Technology, Ministry of Education, Institute of Modern Optics, Nankai University, Tianjin 300071, China.|Department of Chemistry, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada.
authors.forename: Lei
authors.initials: L
authors.lastname: Chen
authors.affiliation: Department of Chemistry, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada.
authors.forename: Qian
authors.initials: Q
authors.lastname: Liu
authors.affiliation: Key laboratory of Optical Information Science and Technology, Ministry of Education, Institute of Modern Optics, Nankai University, Tianjin 300071, China.
authors.forename: Wei-Gang
authors.initials: WG
authors.lastname: Zhang
authors.affiliation: Department of Chemistry, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada.
authors.forename: Keng C
authors.initials: KC
authors.lastname: Chou