Passively mode-locked thulium-doped fiber laser based on a SWCNTs@AFI saturable absorber

Bimetallic solid solution MAX phase Ti2NbAlC2 as saturable absorber for passively Q-switched Er3+-doped fiber laser

“…device, is widely used in passively Q-switched and modelocked fiber lasers due to its unique optical properties. In the past decade, diverse nonlinear optical materials have been researched as SAs, including graphene [5,6], topological insulators (TIs) [7,8], transition metal dichalcogenides (TMDs) [9,10], black phosphorus (BP) [11], carbon nanotubes (CNTs) [12,13], chromium oxide [14], semiconductor saturable absorber mirrors (SESAMs) [15], etc. Nevertheless, these SA materials have their draw backs, for instance, the low modulation depth of single-layer graphene limits its applications in optical modulation [16], the low damage threshold of nanomaterials-based SAs limits the generation of high energy pulse [17], the complex fabrication process and long recovery time of TIs hinder the ultrafast laser to generate [18], the properties of TMDs is related to the number of layers [19], the easy-oxidative feature of BP in the air is adverse for the longterm stability [20], and the complex design and costly price of SESAMs are still a problem [21].…”