Mid-IR supercontinuum pumped by femtosecond pulses from thulium doped all-fiber amplifier

Abstract

We present a mid-infrared (mid-IR) supercontinuum (SC) light source pumped by femtosecond pulses from a thulium doped fiber amplifier (TDFA) at 2 μm. An octave-spanning spectrum from 1.1 to 3.7 μm with an average power of 253 mW has been obtained from a single mode ZBLAN fiber. Spectral flatness of 10 dB over a 1390 nm range has been obtained in the mid-IR region from 1940 - 3330 nm. It is resulted from the enhanced self phase modulation process in femtosecond regime. The all-fiber configuration makes such broadband coherent source a compact candidate for various applications.

Dispersion measurement of ultra-high numerical aperture fibers covering thulium, holmium, and erbium emission wavelengths

“…This observation was qualitatively confirmed by the calculations provided by Kadel et al, although the absolute values (β2 = 0.13 ps 2 /m and β3 = −5.76·10 −4 ps 3 /m at 2 µm [6]) overestimate the measurements, as was also the case for the other investigated UHNA fibers. Two more dispersion values for UHNA7 can be found in literature (β2 = 0.09 ps 2 /m and β3 = −3.3·10 −5 ps 3 /m at 1.92 µm [8]; D = −49.56 ps/nm/km (β2 = ~0.1 ps 2 /m) near 2 µm [28]), although in both cases the origin of these values is unclear as no measurements or references are provided. Hence, we provide the first detailed dispersion measurement for this fiber, yielding much lower absolute dispersion values than those currently available in literature.…”

Broadband and top-flat mid-infrared supercontinuum generation with 3.52 W time-averaged power in a ZBLAN fiber directly pumped by a 2-µm mode-locked fiber laser and amplifier

“…When mid-IR spectral region is concerned, soft glass fibers, including tellurite [5,6], fluoride [1,[7][8][9][10][11][12] and chalcogenide [13,14] fibers can be adopted as nonlinear media. However, among all soft glass fibers, only heavy metal fluoride fibers, including fluorozirconate (ZBLAN) [15][16][17][18][19] and fluoroindate (InF 3 ) [20,21] are technologically mature to be used for multi Watt level SC generation.…”

“…Different types of pulsed thulium-doped fiber-based laser systems, such as mode-locked [18,19], Q-switched and mode-locked [8,23] as well as gain-switched and modelocked [24,25] providing femtosecond [7] and picosecond [23,25] pulses, have been already proposed to pump fluoride fibers. In particular, CW model-locked fiber lasers followed by a cascade of amplifiers delivering optical pulses with pulse widths in the picoseconds range allow scaling output SC power to over 10 W, while being relatively easy in realization.…”

Mid-infrared Supercontinuum Generation to ∼4.7 μm in a ZBLAN Fiber Pumped by an Optical Parametric Generator

“…Their main drawback is a low resistance to moisture, leading to a degradation in air with prolonged exposure. Supercontinuum generation in fluoride fibers pumped with femtosecond [13], [14], picosecond [15], [16], and nanosecond [7], [17] pulses has been reported during the last decade. An ultra-wide SC spectrum extending from ultraviolet to 6.28 μm [13], as well as an SC source emitting an average power as high as 24.3 W [18], generated out of ZBLAN fibers, have been demonstrated.…”