title: Novel characterization technique with 0.5 ppm spatial accuracy of fringe period in Bragg gratings.
abstract: We demonstrate a novel method that can detect period fluctuations of periodic structures such as fiber Bragg gratings at an accuracy of approximately 0.5 ppm. These fluctuations can consist of chirp rates, phase shifts etc. The method can also be used to measure phase masks or work as a position control device with spatial resolution in the order of 10 nm. The technique is a modified side diffraction method with interference between two diffraction orders.
authors.forename: Mattias
authors.initials: M
authors.lastname: Aslund
authors.forename: John
authors.initials: J
authors.lastname: Canning
authors.forename: Leon
authors.initials: L
authors.lastname: Poladian
authors.forename: C
authors.initials: C
authors.lastname: de Sterke