title: Measurement of Hurst exponents for semiconductor laser phase dynamics.
abstract: The phase dynamics of a semiconductor laser with optical feedback is studied by construction of the Hilbert phase from its experimentally measured intensity time series. The Hurst exponent is evaluated for the phase fluctuations and grows from 0.5 to approximately 0.7 (indicating fractional Brownian motion) as the feedback strength is increased. A comparison with numerical computations based on a delay-differential equation model shows excellent agreement and reveals the relative roles of spontaneous emission noise and deterministic dynamics for different feedback strengths.
authors.affiliation: Department of Physics, University of Maryland, College Park, Maryland 20742, USA and IREAP, University of Maryland, College Park, MD 20742, USA.
authors.forename: Wing-Shun
authors.initials: WS
authors.lastname: Lam
authors.forename: Will
authors.initials: W
authors.lastname: Ray
authors.forename: Parvez N
authors.initials: PN
authors.lastname: Guzdar
authors.forename: Rajarshi
authors.initials: R
authors.lastname: Roy