Compact multi-Watt picosecond coherent white light sources using multiple-taper fibers

Abstract

The combination of a diode-pumped Nd:YVO4 picosecond laser source with tapered fibers allows the realization of a compact white light source with an average output power of up to 5.65 W. We generated supercontinua with a throughput of ~50% over a spectral range of up to 1140 nm by using a series of tapered fibers that were spliced together.

Supercontinuum generation and carrier envelope offset frequency measurement in a tapered single-mode fiber

“…Broadband spectra of more than one octave have been generated with ultrashort laser pulses in PCF. An alternative scheme for spectrum broadening is fiber taper technology, which was first applied in conventional single-mode fiber and has since remained quite popular [10][11][12][13][14]. Compared with PCF, the tapered single-mode fiber has a natural double-sided funnel structure which enables light to be focused much more easily and thus generate a supercontinuum (SC) with higher efficiency and stability.…”

“…In addition, the tapered single-mode fiber is able to support high power transmission up to several watts. For example, a multi-watt SC source was set up in cascaded tapered single-mode fibers of different core diameters [13]. An average output power of more than 5 W was obtained.…”

Non-linear applications of microstructured optical fibres

“…However, it is more difficult to reach shorter visible wavelengths with pump sources at 1.06 µm due to the competing requirements of a short zero dispersion wavelength for the phase matching of parametric processes in the visible, and the necessity of pumping in the low anomalous dispersion region of the HF for modulation instability and a long wavelength Raman-soliton continuum. Tapered fibers have recently been used in an attempt to overcome this problem (Teipel et al 2005). As an alternative, here we demonstrate the extension of ytterbium fibre laser pumped supercontinua to wavelengths as short as 0.35 µm, with a high spectral power density, by cascading a number of holey fibers each of which have progressively shorter zero dispersion wavelengths, and therefore advantageous four wave mixing phase matching for the short extension of the continuum.…”

“…Manipulation of the nonlinear contributions by varying the properties of microstructured fibers provides control over the generation of supercontinua to achieve custom, desirable features. For example, tapering of fibers has recently been used to achieve such control (Birks et al 2000;Lu et al 2005;Teipel et al 2005). Here we describe a technique that uses the combination of a number of lengths of un-tapered holey fiber with selected dispersion profiles to generate enhanced, higher average power, continuum components in the blue.…”

“…Tapered fibres with short transition regions ∼1 cm have been investigated previously using both femtosecond (Lu et al 2005) and picosecond pumping (Teipel et al 2005) where supercontinua extending from 460 nm to 1,000 nm were obtained. We report on the application of tapered microstructured fibres, fabricated directly on a fibre drawing tower, with a continuously decreasing dispersion zero wavelength over extended lengths (1-12 m).…”