title: Ultrafast all-optical differentiators.
abstract: We report the experimental realization of an ultrafast all-optical temporal differentiator. Differentiation is obtained via all-fiber filtering based on a simple diffraction grating-assisted mode coupler (uniform long-period fiber grating) that performs full energy conversion at the optical carrier frequency. Due to its high bandwidth, this device allows processing of arbitrary optical signals with sub-picosecond temporal features (down to 180-fs with the specific realizations reported here). Functionality of this device was tested by differentiating a 700-fs Gaussian optical pulse generated from a fiber laser (@ 1535nm). The derivative of this pulse is an odd-symmetry Hermite-Gaussian waveform, consisting of two linked 500-fs-long, pi-phase-shifted temporal lobes. This waveform is noteworthy for its application in advanced ultrahigh-speed optical communication systems.
authors.forename: Radan
authors.initials: R
authors.lastname: Slavík
authors.forename: Yongwoo
authors.initials: Y
authors.lastname: Park
authors.forename: Mykola
authors.initials: M
authors.lastname: Kulishov
authors.forename: Roberto
authors.initials: R
authors.lastname: Morandotti
authors.forename: José
authors.initials: J
authors.lastname: Azaña