title: Second-harmonic generation in single-mode and multimode fibers.
abstract: We report efficient second-harmonic generation in several commercially available telecommunication-grade single-mode and multimode optical fibers. We have investigated the effect of standard dopants such as germanium, phosphorous, and fluorine, and find that the efficient second-harmonic generation is associated with germaniarelated photosensitive color centers. We observed a 1.5% conversion efficiency in single-mode fibers with germanium-, phosphorous-, and fluorine-doped cores and high hydroxyl levels.
authors.forename: M A
authors.initials: MA
authors.lastname: Saifi
authors.forename: M J
authors.initials: MJ
authors.lastname: Andrejco