Dissipative Solitons in Fibre Lasers

Abstract

Iσωeχdiψcipliσaχy cτσcepω τf diψψipaωive ψτliωτσ iψ uσfτlded iσ cτσσecωiτσ wiων ulωχafaψω fibχe laψeχψ. Tνe diffeχeσω mτde-lτckiσμ ωecνσiqueψ aψ well aψ expeχimeσωal χealizaωiτσψ τf diψψipaωive ψτliωτσ fibχe laψeχψ aχe ψuχveyed bχiefly wiων aσ empνaψiψ τσ ωνeiχ eσeχμy ψcal-abiliωy. "aψic ωτpicψ τf ωνe diψψipaωive ψτliωτσ ωνeτχy aχe elucidaωed iσ cτσσecωiτσ wiων cτσcepωψ τf eσeχμy ψcalabiliωy aσd ψωabiliωy. Iω iψ ψντwσ ωνaω ωνe paχameωχic ψpace τf diψψi-paωive ψτliωτσ νaψ χeduced dimeσψiτσ aσd cτmpaχaωively ψimple ψωχucωuχe ωνaω ψimplifieψ ωνe aσalyψiψ aσd τpωimizaωiτσ τf ulωχafaψω fibχe laψeχψ. Tνe maiσ deψωabilizaωiτσ ψceσaχiτψ aχe deψcχibed aσd ωνe limiωψ τf eσeχμy ψcalabiliωy aχe cτσσecωed wiων impacω τf τpωical ωuχ-buleσce aσd ψωimulaωed Ramaσ ψcaωωeχiσμ. Tνe faψω aσd ψlτw dyσamicψ τf vecωτχ diψψipa-ωive ψτliωτσψ aχe expτψed.Keywords: Ulωχafaψω fibχe laψeχ, mτde-lτckiσμ, diψψipaωive ψτliωτσ, στσ-liσeaχ dyσamicψ, vecωτχ ψτliωτσψ, τpωical ωuχbuleσce, ψωimulaωed Ramaσ ψcaωωeχiσμ . IntroductionOveχ ωνe laψω decadeψ, ulωχafaψω fibχe laψeχ ωecνστlτμieψ νave demτσψωχaωed a χemaχkable pχτμχeψψ. "y defiσiωiτσ [ -], ωνeψe ωecνστlτμieψ cτσceχσ μeσeχaωiτσ, maσipulaωiτσ aσd applicaωiτσ τf τpωical pulψeψ fχτm a fibχe laψeχ τχ a laψeχ-amplifieχ ψyψωem wiων i peak pτweχ P 0 exceediσμ ψubψωaσωially aσ aveχaμe laψeχ pτweχ P ave aσd ii pulψe widωνψ wνicν aχe mucν leψψeχ ωνaσ a laψeχ χτuσd-ωχip peχiτd T. Sucν a defiσiωiτσ caσ be χe-iσωeχpχeωed iσ ωeχmψ τf a laψeχ mτde-ρτcπiσμ, wνicν meaσψ a pνaψe-lτcked iσωeχfeχeσce τf ωνe M laψeχ eiμeσmτdeψ pχτduciσμ aσ equidiψωaσω ωχaiσ τf ulωχaψντχω pulψeψ. Tνeσ, ∝ /M M iψ a σumbeχ τf lτcked eiμeσmτdeψ aσd iψ aσ iσωeχ-mτde fχequeσcy iσωeχval defiσed by T ∝ / aσd P 0 ∝ MP ave [ , ]. Iω meaσψ ωνaω a mτde-lτcked laψeχ μeσeχaωeψ a cτmb τf equidiψωaσω τpωical fχequeσcieψ cτmpχiψiσμ ωνe bχτad ψpecωχal χaσμe ∆ ∝ M . Iω iψ cleaχ ωνaω ωνe ψubψωaσωial eσνaσcemeσω τf P 0 by ωνe facωτχ τf M ∝ / ~ ÷ , i.e. upωτ τveχ-MW level [ , ] aσd -χeducωiτσ ~T/M, © 2016 The Author(s). Licensee InTech. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. [ , ]. Tνe exωχaτχdiσaχy peak pτweχψ iσ cτmbiσaωiτσ wiων ωνe dχaψωic pulψe widων decχeaψe bχiσμ ωνe νiμν-field pνyψicψ τσ ωableωτpψ τf a mid-level uσiveχψiωy lab [ -]. Mτχeτveχ, ωνe τveχ-MHz pulψe χepeωiωiτσ χaωeψ pχτvide ωνe ψiμσal χaωe impχτvemeσω facωτχ τf ÷ iσ cτmpaχiψτσ wiων ωνaω τf claψψical cνiχped-pulψe amplifieχψ [ ]. "ψ a χeψulω, ωνe ψiμσal-ωτ-στiψe χaωiτ eσνaσceψ ψubψωaσωially, aψ well."στωνeχ aψpecω τf ωνe ulωχafaψω laψeχ applicaωiτσψ iψ cτσσecωed wiων ψωudyiσμ στσ-liσeaχ pνeστmeσa [ ]. Ulωχafaψω laψeχψ became aσ effecωive plaωfτχm fτχ iσveψωiμaωiτσ τf μeσeχal στσ-liσeaχ pχτceψψeψ ψucν aψ iσψωabiliωieψ aσd χτμue waveψ [ , ], ψelf-ψimilaχiωy [ ] aσd ωuχbu-leσce [ ]. " cτνeχeσω ψelf-τχμaσizaωiτσ iσ ψucν στσ-liσeaχ ψyψωemψ [ , ] iψ ωνe keyψωτσe τ...

Theory of Laser Energy Harvesting at Femtosecond Scale

“…Physically, this type of SAM describes approximately an action of nonlinear polarization rotation, which is a typical ML mechanism for fiber lasers, or a so-called "soft aperture" Kerrlens ML typical for solid-state lasers [24,25]. In this case, loss saturation switches to the loss growth at α 2 ¼ 1=2ζ and…”

“…The first one is based on the unique capacity of laser dissipative solitons (DS) [17,23] to accumulate an energy without loss of stability [24,25]. Some basic approaches to study of the energy-scaling laws for such systems will be presented, and the limits of energy and pulse width scalability will be outlined.…”

“…The mechanisms of ML are beyond the scopes of this work, and we will focus on the principles of the sustained ML energy-scalable regimes at femtosecond scale. The basic principle under consideration is to exploit DS [23] which is extremely stable in nonequilibrium dissipative environment [24,25]. Since DS behaves like a soliton of integrable systems [17,44], its dynamics can be described by some distributed nonlinear model.…”

Self-Organization, Coherence and Turbulence in Laser Optics

“…The key feature of DS is its nontrivial internal structure revealing itself in the phase inhomogeneity 4 and the internal energy redistribution (E is an energy flow): . 3 More precise analysis [27] gives the conditions of asymptotical stability: αγ βκ ≤ 1=3 if E !…”

“…The existence of DS under nonequilibrium conditions requires a well-organized energy exchange with an environment so that this energy flow forms a nontrivial internal structure of DS, which provides the energy redistribution inside it and can distort the soliton coherence. Such a DS with nontrivial internal structure can develop in lasers, and the DS dynamics can become chaotic and turbulent [3][4][5]. For instance, such emergent structures can be considered as a classical analog of Bose-Einstein condensate in low dissipative limit and, contrariwise, as a primitive analog of cell in the case of extensive and wellstructured energy exchange with an environment.…”