Coupling-induced oscillations in nonhomogeneous, overdamped, bistable systems

Coupling-induced oscillations in a homogeneous network of overdamped bistable systems have been previously studied both theoretically and experimentally for a system of N (odd) elements, unidirectionally coupled in a ring topology. In this work, we extend the analysis of this system to include a network of nonhomogeneous elements with respect to the parameter that controls the topology of the potential function and the bistability of each element. In particular, we quantify the effects of the nonhomogeneity on the onset of oscillations and the response of the network to external (assumed to be constant and very small) perturbations, using our (recently developed) coupled core fluxgate magnetometer as a representative system. The potential applications of this work include signal detection and characterization for a large class of sensor systems.     

Environmentally stable all-normal-dispersion femtosecond fiber laser

We demonstrate a mode-locked all-normal-dispersion ytterbium-doped fiber laser constructed with polarization-maintaining fibers. Spectral filtering of a chirped pulse in the cavity, along with a semiconductor saturable absorber, produce self-starting femtosecond mode-locked operation with large normal dispersion. Environmentally stable generation of 2 nJ and 300 fs pulses is achieved.     

Evaluation of an electrochemical sensor based on gold nanoparticles supported on carbon nanofibers for detection of tartrazine dye

Journal of Solid State Electrochemistry - An electrochemical sensor for the detection of tartrazine (Tz), a synthetic azo dye customarily found in commercial soft drinks, is herein reported. This...