title: Precise measurement of single-mode fiber lengths using a gain-switched distributed feedback laser with delayed optical feedback.
abstract: A simple method to measure single-mode optical fiber lengths is proposed and demonstrated using a gain-switched 1.55-μm distributed feedback laser without a fast photodetector or an optical interferometer. From the variation in the amplified spontaneous emission noise intensity with respect to the modulation frequency of the gain switching, the optical length of a 1-km single-mode fiber immersed in water is found to be 1471.043915 m ± 33 μm, corresponding to a relative standard deviation of 2.2 × 10(-8). This optical length is an average value over a measurement time of one minute under ordinary laboratory conditions.
authors.forename: Kenji
authors.initials: K
authors.lastname: Wada
authors.forename: Satoru
authors.initials: S
authors.lastname: Matsukura
authors.forename: Amaka
authors.initials: A
authors.lastname: Tanaka
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Matsuyama
authors.forename: Hiromichi
authors.initials: H
authors.lastname: Horinaka