Ultraviolet-enhanced supercontinuum generation in uniform photonic crystal fiber pumped by a giant-chirped fiber laser

Abstract

We report on an ultraviolet-enhanced supercontinuum generation in a uniform photonic crystal fiber pumped by a giant-chirped mode-locked Yb-doped fiber laser. We find theoretically and experimentally that the initial pluses with giant chirp leads more initial energy transferred to the dispersive waves in visible and ultraviolet wavelength. An extremely wide optical spectrum spanning from 370 nm to beyond 2400 nm with a broad 3 dB spectral bandwidth of 367 nm (from 431 nm to 798 nm) is obtained. Over 36% (350 mW) of the total output power locates in the visible and ultraviolet regime between 370 nm and 850 nm with a maximum spectral power density of 1.6 mW/nm at 550 nm.

Octave-spanning supercontinuum generation in highly nonlinear silica fibres based on cost-effective fibre amplifiers

“…Moreover, a spectrum from 400 nm to 2200 nm by photonic crystal fibre is reported in Ref. 4. Nevertheless, due to the use of silica-based fibre, there exists an upper limit over 2000 nm.…”

“…Although different setups are compared in both references, only one of them obtains a wider spectrum, from 800 nm to 2400 nm, and only another of them offers longer wavelengths, up to 2500 nm, but beginning in 1500 nm. Moreover, a spectrum from 400 nm to 2200 nm by photonic crystal fibre is reported in [4]. Nevertheless, due to the use of silica-based fibre, there exists an upper limit over 2000 nm.…”

“…Moreover, they offer a broad spectrum spanning over several thousand of nanometres with a high spectral power density (>1 mW nm −1 ) in near and medium infrared ranges. These sources usually employ Er and Er/Yb doped fibre pulsed lasers [2] to pump different types of fibres as nonlinear medium: photonic crystal fibres [3][4][5][6] generating up to 2.4 µm, silica highly nonlinear fibres [7][8][9][10][11][12][13] up to 2.7 µm and ZBLAN nonlinear fibres [14][15][16] up to 4.5 µm. Other authors [17][18][19] have reported supercontinuum assisted by thulium-doped fibres generating powers from 2 to 2.5 µm.…”