High-power supercontinuum spanning over more than an octave was generated using a high power femtosecond fiber laser amplifier and multicore nonlinear photonic crystal (PCF). Long PCFs (as long as 20 m in our experiments) are shown to enable generation isolated fundamental supermode, with the manifold of other PCF modes suppressed due strong evanescent fields coupling between cores, providing robust 5.4 W coherent output spatial spectral quality within range wavelengths from 500 1700 nm.

We report on a double negative curvature anti-resonance hollow core fiber, in which, the cladding is constituted of 6 large tubes and small arranged staggered pattern. The simulation shows that loss fiber can reach or even exceed double-clad fibers short wavelength band, due to arrangement two kind boundary. best single mode performance with ratio as high 100,000 between LP11 LP01 obtained simultaneously inhibited modes LP21 structure. reason for oscillations long band fabrication...

The gain bandwidth of the erbium-doped fiber amplifier limits enhancement transmission capacity in optical communication systems. This Letter reports an erbium-ytterbium co-doped phosphosilicate fiber, which is expected to increase by extending L-band 1623 nm. was fabricated modified chemical vapor deposition combined with solution doping technology. mechanism bandwidth-expansion inhibiting signal excited-state absorption investigated. When power and pump were maintained at -3.7dBm ∼720mW...

The 1.5-µm fiber laser is widely used in the fields of lidar, remote sensing, and gas monitoring because its advantages being eye-safe exhibiting low atmospheric transmission loss. However, due to ∼1-µm amplified spontaneous emission (ASE) Er/Yb co-doped (EYDF), it difficult improve power. Here, we simulated effect Er3+ concentration seed power on ASE, fabricated a large mode area EYDF by modified chemical vapor deposition process. Additionally, piece ytterbium-doped was introduced into...

Bismuth-doped germanosilicate fiber (BGSF), the active media of amplifiers, has attracted widespread attention. Here, we report a BGSF with high bismuth concentration 0.075 wt. % and achieve high-efficiency E + S-band amplification, which was prepared by modified chemical vapor deposition (MCVD) process. The small signal absorption (SSA) unsaturated loss (UL) at 1310 nm are 1.32 0.11 dB/m, respectively. results show record only 45 m created, to best our knowledge, provides maximum gain 39.24...

A low-numerical aperture (NA) confined-doped long-tapered (LCT) Yb-doped fiber is proposed and fabricated by modified chemical vapor deposition combined with solution doping technique. The LCT owns the core NA of ∼0.05 gain dopant diameter ratio ∼77%, a core/cladding 25/400 µm at both ends 37.5/600 in middle. laser performance demonstrated bidirectional pumping all-fiber amplifier, which 4.18-kW single-mode (M2 factor ∼1.3) output achieved slope efficiency ∼82.8%. Compared conventional...

A gain-tailored Ge-free Yb/Ce codoped aluminosilicate fiber is fabricated by MCVD combined with solution doping technique. Through regulating the temperature in tube and designing process, refractive index profile of this close to a step-index without any center dip. The laser performance proved through contrast experiments conventional kW-level MOPA setup. amplifier presents beam quality M2 ~1.43 at 1.2 kW. Its MI threshold 1.25 kW, about 1.74 times as much that amplifier. slope efficiency...

Withthe advent of the 5G era, demand for data communication is increasing explosively. Extending L-band gain bandwidth considered to be most direct and effective approach capacity. However, signal excited state absorption (SESA) prevents from extending longer wavelength. In this report, Er <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3+</sup> Ce are introduced into phosphosilicate fiber regulate SESA. The results show that addition Ce3+ can...

We proposed and experimentally demonstrated a high temperature fiber sensor using hetero-structured cladding solid-core photonic bandgap (HCSC-PBGF) for the first time to our knowledge. A is designed fabricated that supports vibrant core mode transmission. Then, an all M-Z interference constructed by splicing single at both ends of HCSC-PBGF without any other micromachining. The transmission characteristics are analyzed with full-vector beam propagation method finite element method,...

We systematically investigated the dependence of mode instability (MI) thresholds on bending diameters in ytterbium-doped fiber amplifiers. The MI a amplifier, which was based multimode fiber, were measured at various diameters. It is found that correlation between and depends operation state active fiber. When few-mode operation, threshold successfully raised from 717 W to 1084 by increasing diameter 11 cm 60 cm. operates quasi-single mode, 953 reducing 8 According our experiments previous...

Mode division multiplexing (MDM) is considered to be an efficient solution alleviate the exponentially increasing "capacity crunch". Here, we numerically and experimentally demonstrate a high power-efficiency, low differential mode gain (DMG) few-mode amplifier based on M-type double-cladding Er/Yb co-doped phosphosilicate fiber. With large-signal power of 4.1 dBm, average DMG <1.5 dB maximum >28 were achieved for LP <sub xmlns:mml="http://www.w3.org/1998/Math/MathML"...

In this work, a record output power of 4.6 kW linearly polarized and narrow-linewidth fiber amplifier based on an optimized oscillator laser (FOL) seed was realized by employing homemade polarization-maintaining Yb-doped (PMYDF), corresponding to slope efficiency 79.5% 3 dB linewidth 0.3452 nm. Through effective strategy relying decreasing the transmission length from 200 m 120 adding chirped tilted Bragg grating (CTFBG), stimulated Raman scattering (SRS) effects were well-suppressed. By...

We report a bismuth-doped fiber with high bismuth active center concentration and low unsaturable loss, demonstrating record 16m E+S-band amplifier 47.9dB gain per unit length of 4.06dB/m at 1450nm.

We report on the strong photo-bleaching of photo-darkening (PD) induced loss under cladding pump a 793 nm laser diode (LD) in double clad Yb-doped fibers. Up to 68% PD at 810 was bleached. The bleaching rates different powers show that higher power corresponds more bleached within same time. Moreover, repeatable processes and were observed when alternately pumped with 915 LDs. Furthermore, it found simultaneously pumping fiber LDs can suppress about 80% loss, compared only LD. mechanism also...

A confined-doped fiber was fabricated by a modified chemical vapor deposition (MCVD) process based on refractive index matching technology. With theory and experiments, we compared the normal-doped fiber. We found that with core of 35 μm 0.07 numerical aperture could achieve single-mode output improve beam quality from 2.8 to 1.5 in laser. Meanwhile, it still possesses high laser efficiency has good stability increase pump power. It suggests MCVD may be key material for high-power excellent quality.

Broadband ∼2 μm amplified spontaneous emissions with a full width at half-maximum (FWHM) varying from ∼206 to ∼234 nm were obtained the Ho/Cr/Tm:yttrium aluminum garnet (YAG) crystal derived fibers, which drawn using molten core method. The core-cladding structure of as-drawn fibers was preserved completely, and found be amorphous. What is more, an all-fiber-integrated passively mode-locked laser based on 8 cm long Ho/Cr/Tm:YAG all-glass fiber built which, best our knowledge, first...

Spatial division multiplexing (SDM) is one of the most important technologies that may help to solve future capacity crisis. However, date, SDM optical amplification still a challenge for its application. Herein, we numerically and experimentally demonstrated few-mode Er/Yb co-doped fiber amplifier (FM-EYDFA) extended L-band operation. A double cladding was fabricated expand bandwidth novel, best our knowledge, cladding-pumped pseudo-two-stage configuration proposed enhance gain. With an...

We report on the preparation and optical characteristics of an Yb(3+)-doped large core silica fiber with active prepared from nanoporous rod by glass phase-separation technology. The measurements show that has Yb(3+) concentration 9811 ppm weight, a low background attenuation 0.02 dB/m, absorption about 5.5 dB/m at 976 nm. laser performance presents high slope efficiency 72.8% for emission 1071 nm threshold 3 W within only 2.3 m length. It is suggested technology shows great potential...

In this work, a narrow-linewidth linearly polarized fiber amplifier with record output power of 3.2 kW was achieved based on homemade polarization-maintaining Yb-doped corresponding to slope efficiency 79% and 3 dB linewidth 0.2227 nm. By examining various numerical aperture (NA) PMYDFs, the experimental investigation expanding mode instability (MI) threshold in PM amplifiers put display. And results reveal that MI is enhanced by more than 370 W for every 0.004 decrease core aperture....

In this work, Na+ ions doping into the Yb-doped fiber is proposed to improve photo-darkening resistance. The results show that induced excess loss at equilibrium state 633nm, 702 nm, 810 and 1041 nm 115.54dB/m, 86.87dB/m, 25.51 dB/m, 2.92 respectively, when co-doping with ions. More than 30% reduced comparing without mechanism of mitigate PD discussed. Besides, we measured laser efficiency Yb/Al/Na co-doped be 76.1%. This result remains almost same proves addition do not deteriorate slope...

We report a novel center-sunken and cladding-trenched Yb-doped fiber, which was fabricated by modified chemical vapor deposition process with solution-doping technique. The simulation results showed that the fiber core diameter of 40 µm numerical aperture 0.043 has 1217 µm2 effective mode area at 1080 nm. It is also disclosed leakage loss can be reduced lower than 0.01 dB/m for LP01 mode, while over 80 LP11 optimizing bending radius as 14 cm. A 456 W laser output observed in MOPA structure....

We report a numerical investigation on trench-assisted few-mode erbium-doped fiber amplifier supporting 6 spatial modes with very low differential modal gain. The is based the experimentally measured parameters of extended L-band Er 3+ doped fiber. results show that gain covering spectral range from 1570 to 1616 nm was reduced as 0.28 dB by mode hybrid core pumped architecture at 1550 pump wavelength. Compared cladding pumping, our method achieved efficiency increased 23.1% and smaller when...