title: Thermoacoustic optical path length stabilization in a single-mode optical fiber.
abstract: We present a simple technique to actively stabilize the optical path length in an optical fiber. A part of the fiber is coated with a thin, electrically conductive layer, which acts as a heater. The optical path length is thus modified by temperature-dependent changes in the refractive index and the mechanical length of the fiber. For the first time, we measure the dynamic response of the optical path length to the periodic changes of temperature and find it to be in agreement with our former theoretical prediction. The fiber's response to the temperature changes is determined by the speed of sound in quartz rather than by slow thermal diffusion. Making use of this fact, we succeeded in actively stabilizing the optical path length with a closed-loop bandwidth of 3.8 kHz.
authors.affiliation: Institute of Physics, Humboldt University of Berlin, Hausvogteiplatz 5-7, 10117 Berlin, Germany. lewoczko@physik.hu-berlin.de
authors.forename: Wojciech
authors.initials: W
authors.lastname: Lewoczko-Adamczyk
authors.forename: Max
authors.initials: M
authors.lastname: Schiemangk
authors.forename: Holger
authors.initials: H
authors.lastname: Müller
authors.forename: Achim
authors.initials: A
authors.lastname: Peters
mesh_terms: D000162:Acoustics / Q000295:instrumentation*; D017076:Computer-Aided Design; D004867:Equipment Design; D019544:Equipment Failure Analysis; D008027:Light; D055100:Optical Fibers; D012542:Scattering, Radiation