title: Highly sensitive spectral interferometric four-wave mixing microscopy near the shot noise limit and its combination with two-photon excited fluorescence microscopy.
abstract: We present spectral interferometric four-wave mixing (FWM) microscopy with a nearly shot-noise limited sensitivity and with the capability of separating FWM signals from fluorescence signals. We analyze the requirements for obtaining the shot-noise limited sensitivity and experimentally achieve the sensitivity that is only 4-dB lower than the shot-noise limit. Moreover, we show that only FWM signals can be extracted through the Fourier filtering even when the FWM spectrum is overlapped and overwhelmed by the fluorescence spectrum. We demonstrate simultaneous acquisition of FWM and two-photon excited fluorescence images of fluorescent monodispersed polystyrene microspheres.
authors.forename: Keisuke
authors.initials: K
authors.lastname: Isobe
authors.forename: Yasuyuki
authors.initials: Y
authors.lastname: Ozeki
authors.forename: Takehito
authors.initials: T
authors.lastname: Kawasumi
authors.forename: Shogo
authors.initials: S
authors.lastname: Kataoka
authors.forename: Shin'ichiro
authors.initials: S
authors.lastname: Kajiyama
authors.forename: Kiichi
authors.initials: K
authors.lastname: Fukui
authors.forename: Kazuyoshi
authors.initials: K
authors.lastname: Itoh