Supercontinuum

About: Supercontinuum is a research topic. Over the lifetime, 7071 publications have been published within this topic receiving 127671 citations.

Dual-band Tm 3+ -doped tellurite fiber amplifier and laser at 1.9 μm and 2.3 μm

Abstract: Ultrabroadband amplification and two-color CW lasing simultaneously near 1.9 μm and 2.3 μm in a Tm3+-doped tellurite fiber were demonstrated experimentally, for the first time to the best of our knowledge. A low-loss Tm3+-doped core fiber from TeO2–ZnO–La2O3–Na2O glasses stable against crystallization was produced by a special technique, providing a low concentration of hydroxyl groups. Supercontinuum from a highly GeO2 doped silica fiber pumped by an Er fiber laser system was used as a seed for an amplifier. A maximum gain of 30 dB and 7 dB was measured at 1.9 μm and 2.3 μm, respectively. We report detailed experimental and theoretical studies, which are in a very good agreement, of laser amplification and generation in the manufactured fiber with carefully measured and calculated parameters. A quantitatively verified numerical model was used to predict power scalability at 2.3 μm in schemes with optimized parameters at increased pump power. The presented results show that a high-quality tellurite fiber is a promising candidate for developing lasers in the 2.3 μm atmospheric window which are particularly relevant for applications in gas sensing, eye-safe laser radars, breath analysis, remote sensing and stand-off trace gas detection.

Broadband mid-infrared supercontinuum generation in dispersion-engineered silicon-on-insulator waveguide

Abstract: In this paper, we numerically investigate near- and mid-infrared supercontinuum (SC) generation in dispersion-engineered silicon-on-insulator (SOI) waveguides employing a novel side-slotted core structure. The effect of waveguide parameters on the dispersion is studied to achieve optimum dispersion profiles for SC generation in the anomalous and normal dispersion regimes. Numerical results show that by applying an input pump pulse with 200 fs width and 400 W peak power at 2.1 μm wavelength in a 10-mm-long SOI waveguide, SC spectra as wide as 2.8 μm and 2.0 μm can be obtained in the anomalous and normal dispersion regimes, respectively. These waveguides are useful as compact on-chip silicon photonic sources for spectroscopic applications in mid-infrared wavelengths.

Supercontinuum generation in water by intense, femtosecond laser pulses under anomalous chromatic dispersion

Abstract: We report efficient generation of a broadband supercontinuum (SC) in water upon irradiation by intense, near-infrared, femtosecond laser pulses. The SC spectra generated when the pump wavelength lies in the anomalous chromatic dispersion region are characterized by largely blueshifted peaks in the visible range. These SC spectral features are rationalized within the framework of a phenomenological self-phase-modulation model, taking into account higher-order group velocity dispersion. Our model provides an intuitive explanation for the relation between the observed pump-wavelength dependence of the blueshifted SC peaks and the anomalous chromatic dispersion.

Versatile supercontinuum generation in parabolic multimode optical fibers

Abstract: We demonstrate that the pump's spatial input profile can provide additional degrees of freedom in tailoring at will the nonlinear dynamics and the ensuing spectral content of supercontinuum generation in highly multimoded optical fibers. Experiments and simulations carried out at 1550 nm indicate that the modal composition of the input beam can substantially alter the soliton fission process as well as the resulting Raman and dispersive wave generation that eventually lead to supercontinuum in such a multimode environment. Given the multitude of conceivable initial conditions, our results suggest that it is possible to pre-engineer the supercontinuum spectral content in a versatile manner.

Multioctave supercontinuum generation and frequency conversion based on rotational nonlinearity.

Abstract: The field of attosecond science was first enabled by nonlinear compression of intense laser pulses to a duration below two optical cycles. Twenty years later, creating such short pulses still requires state-of-the-art few-cycle laser amplifiers to most efficiently exploit “instantaneous” optical nonlinearities in noble gases for spectral broadening and parametric frequency conversion. Here, we show that nonlinear compression can be much more efficient when driven in molecular gases by pulses substantially longer than a few cycles because of enhanced optical nonlinearity associated with rotational alignment. We use 80-cycle pulses from an industrial-grade laser amplifier to simultaneously drive molecular alignment and supercontinuum generation in a gas-filled capillary, producing more than two octaves of coherent bandwidth and achieving >45-fold compression to a duration of 1.6 cycles. As the enhanced nonlinearity is linked to rotational motion, the dynamics can be exploited for long-wavelength frequency conversion and compressing picosecond lasers.