Broadband optical supercontinuum generation in a long cavity fibre laser

We describe optical supercontinuum generation in an actively mode-locked fibre ring laser using a pulsed mode-locking technique. Recirculation of a section of the continuum facilitated spectral broadening

Ge-Doped microstructured multicorefiber for customizable supercontinuum generation

Supercontinuum generation in a multicore fiber in which several uncoupled cores were doped with dissimilar concentrations of germanium was studied experimentally. Germanium doping provided control over the separation between the zero-dispersion wavelength and the 1064-nm wavelength of a Q-switched Nd:YAG pump laser. Supercontinua generated independently in each core of the same piece of fiber displayed clear and repeatable differences due to the influence of germanium doping on refractive index and four-wave mixing. The spectral evolution of the subnanosecond pump pulses injected into the different cores was accurately reproduced by numerical simulations

Nonlinear beam cleanup in Yb-doped GRIN multimode fiber taper

We demonstrate beam self-cleaning in a tapered Ytterbium-doped graded- index multimode fiber in both active and passive configurations, without accompanying self-phase modulation induced spectral broadening or frequency conversio

Absolute Interferometric Measurement of Differential Displacements

The paper describes an interferometric technique suitable for the absolute measurement of displacements with nanometer resolution over a range up to few hundreds of micrometers. The displacement pick-ups are linked with optical fibers. The laser source is a VCSEL operated with a continuous wavelength modulation. The measurement is obtained combining absolute frequency-based measurements with phase-based measurements. The uncertainty analysis shows the conditions that must be fulfilled to get the best results. To build a compact sensors it is proposed the use of a DOE as a beam splitter and fiber coupler