Supercontinuum

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

Spatiotemporal Characterization of Supercontinuum Extending from the Visible to the Mid-Infrared in Multimode Graded-Index Optical Fiber

Abstract: We experimentally demonstrate that pumping a graded-index multimode fiber with sub-ns pulses from a microchip Nd:YAG laser leads to spectrally flat supercontinuum generation with a uniform bell-shaped spatial beam profile extending from the visible to the mid-infrared at 2500\,nm. We study the development of the supercontinuum along the multimode fiber by the cut-back method, which permits us to analyze the competition between the Kerr-induced geometric parametric instability and stimulated Raman scattering. We also performed a spectrally resolved temporal analysis of the supercontinuum emission.

Supercontinuum generation with 200 pJ laser pulses in an extruded SF6 fiber at 1560 nm.

Abstract: We report an all-fiber diode-pumped Erbium-fiber oscillator-amplifier system as a source for supercontinuum generation in a photonic crystal fiber at 1560 nm. The passively mode-locked oscillator-amplifier system provides linearly polarized output pulses of 60 fs and an average output power of 59 mW at a repetition rate of 59.1 MHz. The laser pulses were launched into an extruded SF6-fiber for generation of an ultra-broadband supercontinuum. The evolution of the supercontinuum as a function of launched pulse energy was investigated. With pulse energies of about 200 pJ we observed a more than octave-spanning supercontinuum from 400 nm to beyond 1750 nm.

Supercontinuum generation in liquid-filled photonic crystal fiber with slow nonlinear response

Abstract: We theoretically investigate the nonlinear propagation of femtosecond pulses in liquid-core photonic crystal fibers filled with CS2. The effect of slow nonlinearity due to reorientational contribution of liquid molecules on broadband supercontinuum generation in the femtosecond regime is studied using an appropriately modified nonlinear Schrodinger equation. To analyze the quality of the pulse, we perform the stability analysis and study coherence of supercontinuum pulse numerically. We show that the response of the slow nonlinearity not only enhances broadening of the pulse and changes the dynamics of the generated solitons, but also increases coherence of the pulse.

Fiber-based light sources for biomedical applications of coherent anti-Stokes Raman scattering microscopy

Abstract: During the past decade coherent anti-Stokes Raman scattering (CARS) microscopy has evolved to one of the most powerful imaging techniques in the biomedical sciences, enabling the label-free visualization of the chemical composition of tissue in vivo in real time. While the acquisition of high-contrast images of single cells up to large tissue sections enables a wide range of medical applications from routine diagnostics to surgical guidance, to date CARS imaging is employed in fundamental research only, essentially because the synchronized multiple wavelength pulsed laser sources required for CARS microscopy are large, expensive and require regular maintenance. Laser sources based on optical fibers can overcome these limitations combining highest efficiency and peak powers with an excellent spatial beam profile and thermal stability. In this review we summarize the different fiber-based approaches for laser sources dedicated to coherent Raman imaging, in particular active fiber technology and passive fiber-based frequency conversion processes, i.e. supercontinuum generation, soliton self-frequency shift and four-wave mixing. We re-evaluate the ideal laser parameters for CARS imaging and discuss the suitability of different laser concepts for turn-key operation required for routine application in clinics.