title: Formation of Type I-IR and Type II-IR gratings with an ultrafast IR laser and a phase mask.
abstract: The formation of two grating types in SMF-28 fiber by focusing 125 fs, 0.5-2 mJ pulses through a phase mask onto a fiber sample is studied. The first type, specified as type I-IR, occurs below the damage threshold of the medium. The scaling behavior of the type I-IR gratings with field intensity and annealing properties suggests that their formation is related to nonlinear absorption processes, possibly resulting in color center formation. The second type, denoted as type II-IR, occurs coincidentally with white light generation within the fiber. These type II-IR gratings are stable at temperatures in excess of 1000 masculineC and are most likely a consequence of damage to the medium following ionization.
authors.forename: Christopher
authors.initials: C
authors.lastname: Smelser
authors.forename: Stephen
authors.initials: S
authors.lastname: Mihailov
authors.forename: Dan
authors.initials: D
authors.lastname: Grobnic