1,192 research outputs found
1.3 µm dissipative soliton resonance generation in Bismuth doped fiber laser
No full textIn this work, a Figure-9 (F9) bismuth-doped fiber laser (BiDFL) operating in the dissipative soliton resonance (DSR) regime is presented. The 1338 nm laser used a BiDF as the active gain medium, while a nonlinear amplifying loop mirror (NALM) in an F9 configuration was employed to obtain high energy mode-locked pulses. The wave breaking-free rectangular pulse widened significantly in the time domain with the increase of the pump power while maintaining an almost constant peak power of 0.6 W. At the maximum pump power, the mode-locked laser delivered a rectangular-shaped pulse with a duration of 48 ns, repetition rate of 362 kHz and a radio-frequency signal-to-noise ratio of more than 60 dB. The maximum output power was recorded at around 11 mW with a corresponding pulse energy of 30 nJ. This is, to the best of the author’s knowledge, the highest mode-locked pulse energy obtained at 1.3 μm as well as the demonstration of an NALM BiDFL in a F9 configuration.</p
Manual Hydraulic Structures
No full textThis manual is the result of group work and origins in Dutch lecture notes that have been used since long time. Amongst the employees of the Hydraulic Engineering Department that contributed to this work are dr.ir. S. van Baars, ir.K.G.Bezuijen, ir.G.P.Bourguignon, prof.ir.A.Glerum, dr.ir.P.A.Kolkman, ir. H.K.T. Kuijper, ir. H.G. Voortman and prof.drs.ir. J.K. Vrijling. The latest years, this manual has been clarified, revised and expanded by ir. W.F. Molenaar and ing. M.Z. Voorendt. We have received much feedback from students and got good input from our student-assistants, which is highly appreciated and has been taken taken into account for this new edition. In the 2016 edition, some minor corrections were made throughout the Manual, most noticeably the equation for the spring stiffness of a combined system in Section 29.2. Section 11.1 has been updated with more generic weir discharge equations. Furthermore, serviceability requirements have been added to the chapter on wave-overtopping (Chapter 17) and the Blum theory for laterally loaded piles has been better explained in Chapter 44. The largest change is the addition of Chapter 49, about the determination of the height of flood defences
Author Correction:A 41,500 year-old decorated ivory pendant from Stajnia Cave (Poland)
No full textCorrection to: Scientific Reports https://doi.org/10.1038/s41598-021-01221-6, published online 25 November 2021The original version of this Article contained errors in the author list where Marjolein D. Bosch was omitted from the author list, and Mikołaj Urbanowski was incorrectly listed as an author of the original Article, and has subsequently been removed.The Author contributions section now reads:“S.T. W.N. and A.N. conceived the project; S.T., W.N., A.P., M.B., S.C., M.D., H.F., A.M., M.D. B., D.P., M.P.R., C.M.R., V.S-M., G.M.S., P.S., M.S., K.S., A.V., F.W., H.W., A.W., M.Z., S.B., A.N., J-J. H., performed research; S.T., A.P., W.N., M.B., M.D.B., S.C., M.D., H.F., A.M., D.P., M.P.R., C.M.R., V.S-M., G.M.S., P.S., M.S., K.S., A.V., F.W., H.W., A.W., M.Z., S.B., A.N., J-J. H. analysed all archaeological data; S.T. and A.P. wrote the paper with the collaboration of all the co-authors.”The original Article and its accompanying Supplementary Information file have been corrected
1.3 μm passively Q-Switched bismuth doped fiber laser using Nb<sub>2</sub>C saturable absorber
No full textA tunable passively Q-switched fiber laser operating at 1.3 μm was demonstrated using bismuth-doped fiber (BDF) as the gain medium and using niobium carbide (Nb2C) as the saturable absorber (SA). The Nb2C was prepared using the solution casting method, and then fabricated into a film form for ease of integration into the laser cavity. Stable Q-switched pulses were observed as the pump power was increased from 820 to 1037 mW, generating pulses with increasing repetition rates from 10.1 kHz to 13.8 kHz and decreasing pulse widths from 17.54 to 7.58 μs. The all-fiber laser had a center wavelength at 1314 nm with a broad 3-dB bandwidth of 8.35 nm. The maximum output power and pulse energy of the Q-switched laser were 0.74 mW and 53.7 nJ, respectively. The laser was stable when tested for its long-term stability, where the peak frequency remained consistent at 13.8 kHz and the SNRs were maintained to be more than 60 dB throughout the entire test period. To the best of our knowledge, this is the first demonstration for a passively Q-switched fiber laser operating at 1.3 μm wavelength region using BDF as the gain medium
Multi-wavelength Bismuth-doped fiber laser in 1.3 µm based on a compact two-mode fiber filter
No full textIn this work, a multi-wavelength Bismuth-doped fiber laser (MWLBDFL) operating in the 1.3 µm wavelength region is presented and experimentally demonstrated. The MWLBDFL leveraged on a 60 m Bismuth-doped fiber as an active gain medium, a compact two-mode fiber filter (TMFF) as a comb filter and a 2 km single-mode fiber section to induce four-wave mixing in the system. By optimising the polarization controller, the MWLBDFL generated 18 stable lasing output channels within 10 dB from the highest lasing line and a reasonably flat spectrum over a range of 11 nm. The stability of the MWLBDFL tested for a 150-minute duration showed a peak power fluctuation of less than 1 dB with a negligible wavelength drift. The extinction ratio of the TMFF was approximately 8.6 dB while the highest and lowest optical-signal-to-noise ratios (OSNRs) of the MWLBDFL were ~ 55 dB and ~ 50 dB, respectively. To the best of the author's knowledge, the proposed MWLBDFL demonstrates the highest number of output channels compared to other MWLs operating in the same wavelength region.</p
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