title: In-fiber Mach-Zehnder interferometer and sphere whispering gallery mode resonator coupling structure.
abstract: An in-fiber Mach-Zehnder interferometer and sphere whispering gallery mode resonator coupling structure is demonstrated by femtosecond laser micromachining. Asymmetric spectra around the resonant wavelength of the whispering gallery cavities in different coupling states are experimentally observed. An extinction ratio of ∼7  dB and a slope of 117 dB/nm can be achieved in the asymmetric spectrum of the overcoupled whispering gallery cavity, where an additional π phase shift at the resonant wavelength is introduced to the Mach-Zehnder interferometer.
authors.forename: Leilei
authors.initials: L
authors.lastname: Shi
authors.forename: Tao
authors.initials: T
authors.lastname: Zhu
authors.forename: Dongmei
authors.initials: D
authors.lastname: Huang
authors.forename: Chuancan
authors.initials: C
authors.lastname: Liang
authors.forename: Min
authors.initials: M
authors.lastname: Liu
authors.forename: Shibin
authors.initials: S
authors.lastname: Liang