Browsing by Subject "Solitons"
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Item Open Access 10-W, 156-MHz all-fiber-integrated Er-Yb-doped fiber laser-amplifier system(Optical Society of America, 2012) Pavlov, Ihor; İlbey, Emrah; Dülgergil, Ebru; İlday, Fatih ÖmerWe demonstrate all-fiber, high-power chirped-pulse-amplifier system, operating at 1550 nm. 156-MHz soliton oscillator seeds a two-stage single-mode amplifier with output power of 10 W. After external compression, pulse duration is 0.6 ps. © 2012 Optical Society of America.Item Open Access All-fiber all-normal-dispersion femtosecond laser with nonlinear multimodal interference-based saturable absorber(Institute of Electrical and Electronics Engineers Inc., 2019) Teğin, Uğur; Ortaç, BülendChong et al. demonstrated a stable passively mode-locked all-normal-dispersion fiber laser and pulse generation is attributed to the strong spectral filtering of chirped pulses, dissipative soliton pulses [1]. In the following years, with very-large-mode-area fibers the energy and power scalability of the dissipative soliton pulses is demonstrated. Recently, multimodal interactions are subject to device studies with various configurations. Nazemosadat et al. theoretically proposed a short graded-index multimode fiber segment in between single mode fiber as a saturable absorber [2]. On the other hand, with similar device structure an all-fiber bandpass filter is later presented both numerically and experimentally [3].Item Open Access All-fiber nonlinearity-and dispersion-managed dissipative soliton nanotube mode-locked laser(American Institute of Physics, 2015) Zhang Z.; Popa, D.; Wittwer, V. J.; Milana, S.; Hasan, T.; Jiang, Z.; Ferrari, A. C.; Ilday F. Ö.We report dissipative soliton generation from an Yb-doped all-fiber nonlinearity- and dispersion-managed nanotube mode-locked laser. A simple all-fiber ring cavity exploits a photonic crystal fiber for both nonlinearity enhancement and dispersion compensation. The laser generates stable dissipative solitons with large linear chirp in the net normal dispersion regime. Pulses that are 8.7 ps long are externally compressed to 118 fs, outperforming current nanotube-based Yb-doped fiber laser designs.Item Open Access All-fiber-integrated soliton-similariton laser with in-line fiber filter(Optical Society of America, 2012-08-16) Zhang, Z.; Öktem, B.; Ilday, F. Ö.We demonstrate an all-fiber-integrated Er-doped fiber laser operating in the soliton-similariton mode-locking regime. In the similariton part of the cavity, a self-similarly evolving parabolic pulse with highly linear chirp propagates in the presence of normal dispersion. Following an in-line fiber-based birefringent filter, the pulse evolves into a soliton in the part of the cavity with anomalous dispersion. The similariton and the soliton pulses are dechirped to 75.5 and 167.2 fs, respectively, outside of the cavity. Mode-locked operation is very robust, owing to the influence of the two similariton and soliton attractors that predominate each half of the laser cavity. The experimental results are supported with numerical simulations, which provide good agreement.Item Open Access Amplitude noise of femtosecond fiber lasers in different modelocking regimes(OSA, 2007) Budunoğlu, İbrahim Levent; İlday, Fatih ÖmerAmplitude noise of femtosecond fiber laser oscillators are characterized in soliton, similariton, stretched-pulse and all-normal GVD regimes of mode-locking. Integrated relative intensity noise as low as 0.023% (1 Hz-100 kHz) is reported.Item Open Access Bell solitons in ultra-cold atomic Fermi gas(2013) Khan, A.; Panigrahi P.K.We demonstrate the existence of supersonic bell solitons in the Bardeen-Cooper-Schrieffer-Bose-Einstein condensate crossover regime. Starting from the extended Thomas-Fermi density functional theory of superfluid order parameter, a density transformation is used to map the hydrodynamic mean field equation to a Lienard-type equation. As a result, bell solitons are obtained as exact solutions, which is further verified by the numerical solution of the dynamical equation. The stability of the soliton is established and its behaviour in the entire crossover domain is obtained. It is found that, akin to the case of vortices, bell solitons yield highest contrast in the BEC regime. © 2013 IOP Publishing Ltd.Item Open Access Generation of dissipative solitons in normal-dispersion Raman fiber laser(IEEE, 2016) Teğin, Uğur; Elahi, Parviz; Şenel, Ç.; Ergeçen, E.; İlday, Fatih ÖmerDissipative soliton pulses in a synchronously pumped all-normal-dispersion Raman fiber laser is presented theoretically and experimentally. The laser generates 7.1 nJ intra-cavity pulses at 1.12 μm and is compressed to 136 fs.Item Open Access Generation of soliton molecules with independently evolving phase in a mode-locked fiber laser(Optical Society of America, 2010) Ortaç, Bülend; Zaviyalov, A.; Nielsen, C.K.; Egorov, O.; Iliew, R.; Limpert, J.; Lederer, F.; Tünnermann, A.We report the experimental generation of two-soliton molecules in an ytterbium-doped fiber laser. These molecules exhibit an independently evolving phase and are characterized by a regular spectral modulation pattern with a modulation depth of 80%. © 2010 Optical Society of America.Item Open Access High energy dissipative raman soliton laser through XPM stabilization(Optical Society of America (OSA), 2015-10) Ergeçen, E.; Tegin, Uğur; Elahi, Parviz; Şenel, Ç.; İlday, F. ÖmerDispersion, nonlinearity and gain determine the intracavity pulse behaviour. We show that pump depletion and XPM play a significant role in the stabilization of high energy dissipative Raman solitons. Using this theoretical knowledge, we predict and demonstrate 7-nJ femtosecond pulses at 1120 nm. © OSA 2015.Item Open Access The Hirota direct method(2005) Pekcan, AslıThe search for integrability of nonlinear partial differential and difference equations includes the study on multi-soliton solutions. One of the most famous method to construct multi-soliton solutions is the Hirota direct method. In this thesis, we explain this method in detail and apply it to explicit examples.Item Open Access Nonlinear chirped-pulse amplification of a soliton-similariton laser to ~1 µJ at 1550 nm(Optical Society of America, 2012) İlbey, Emrah; Pavlov, Ihor; Dülgergil, E.; Öktem, Bülent; Yavas, Seydi; Rybak, Andrii; Zhang, Zuxing; İlday, Fatih ÖmerWe demonstrate all-fiber-integrated nonlinear CPA system operating at 1550 nm, seeded by a soliton-similariton laser. Chirped 2-μJ pulses are compressed to 700-fs, 0.5-μJ pulses at 1 MHz. Amplifier output is through a strictly singlemode fiber. © 2012 OSA.Item Open Access Nonlinearity engineering of mode-locked fiber lasers: Similariton and soliton-similariton lasers(IEEE, 2011) İlday F. Ömer; Öktem, Bülent; Ülgüdür, CoşkunFiber lasers are attractive with their simplicity, high powers and low cost. However, propagation of short pulses in optical fiber leads to nonlinear effects, which limit the technical performance. These effects drive rich dynamics, which is interesting from a fundamental perspective. The nonlinear waves community has unraveled the fascinating world of solitons and similaritons through experiments in fibers. This paper overviews the recent development of the soliton-similariton laser. The original similariton laser was the first to work with nonlinear effects, rather than minimizing or compensating them. In the soliton-similariton laser, the propagation is strongly nonlinear everywhere. © 2011 IEEE.Item Open Access Observation of soliton molecules with independently evolving phase in a mode-locked fiber laser(2010) Ortaç, B.; Zaviyalov, A.; Nielsen, C.K.; Egorov O.; Iliew, R.; Limpert J.; Lederer F.; Tünnermann, A.We report the experimental generation of two-soliton molecules in an all-polarization-maintaining ytterbium-doped fiber laser operating in the normal dispersion regime. These molecules exhibit an independently evolving phase and are characterized by a regular spectral modulation pattern with a modulation depth of 80% measured as an averaged value. Moreover, the numerical modeling confirms that the limited modulation depth of the spectrum is caused by the evolution of the phase difference between the pulses. © 2010 Optical Society of America.Item Open Access Soliton-similariton fibre laser(Macmillan Publishers, 2010-03-21) Öktem, Bülent; Ülgüdür, Coşkun; İlday, F. ÖmerRapid progress in passively mode-locked fibre lasers is currently driven by the recent discovery of new mode-locking mechanisms, namely, the self-similarly evolving pulse (similariton) and the all-normal-dispersion (dissipative soliton) regimes. These are fundamentally different from the previously known soliton and dispersion-managed soliton (stretched-pulse) regimes. Here, we report a fibre laser in which the mode-locked pulse evolves as a similariton in the gain segment and transforms into a regular soliton in the rest of the cavity. To our knowledge, this is the first observation of similaritons in the presence of gain, that is, amplifier similaritons, within a laser cavity. The existence of solutions in a dissipative nonlinear cavity comprising a periodic combination of two distinct nonlinear waves is novel and likely to be applicable to various other nonlinear systems. For very large filter bandwidths, our laser approaches the working regime of dispersion-managed soliton lasers; for very small anomalous-dispersion segment lengths it approaches dissipative soliton lasers. .Item Open Access Solutions of the extended Kadomtsev-Petviashvili-Boussinesq equation by the Hirota direct method(Taylor & Francis Asia Pacific (Singapore), 2009) Pekcan, A.We show that we can apply the Hirota direct method to some non-integrable equations. For this purpose, we consider the extended Kadomtsev-Petviashvili- Boussinesq (eKPBo) equation with M variable which is (uxxx-6uu x)x + a11uxx + 2ΣMk=2 a1kuxk + ΣMi,j=2aijuxixj=0, where aij = a ji are constants and xi = (x, t, y, z,⋯,x M). We will give the results for M = 3 and a detailed work on this equation for M = 4. Then we will generalize the results for any integer M > 4. © 2009 The Author(s).Item Open Access Sub-80 fe dissipative soliton large-mode-area fiber laser(2010) Baumgartl, M.; Ortaç, B.; Lecaplain, C.; Hideur, A.; Limpert J.; Tünnermann, A.We report on high-energy ultrashort pulse generation from an all-normal-dispersion large-mode-area fiber laser by exploiting an efficient combination of nonlinear polarization evolution (NPE) and a semiconductor-based saturable absorber mode-locking mechanism. The watt-level laser directly emits chirped pulses with a duration of 1 ps and 163 nJ of pulse energy. These can be compressed to 77 fs, generating megawatt-level peak power. Intracavity dynamics are discussed by numerical simulation, and the intracavity pulse evolution reveals that NPE plays a key role in pulse shaping. © 2010 Optical Society of America.Item Open Access Weingarten surfaces arising from soliton theory(1999) Ceyhan, ÖzgürIn this work we presented a method for constructing surfaces in associated with the symmetries of Gauss-Mainardi-Codazzi equations. We show that among these surfaces the sphere has a unique role. Under constant gauge transformations all integrable equations are mapped to a sphere. Furthermore we prove that all compact surfaces generated by symmetries of the sine-Gordon equation are homeomorphic to sphere. We also construct some Weingarten surfaces arising from the deformations of sine-Gordon, sinh-Gordon, nonlinear Schrödinger and modified Korteweg-de Vries equations.