Versatile Mode-Locked Operations in an Er-Doped Fiber Laser with a Film-Type Indium Tin Oxide Saturable Absorber

Abstract

We demonstrate the generation of versatile mode-locked operations in an Er-doped fiber laser with an indium tin oxide (ITO) saturable absorber (SA). As an epsilon-near-zero material, ITO has been only used to fashion a mode-locked fiber laser as an ITO nanoparticle-polyvinyl alcohol SA. However, this type of SA cannot work at high power or ensure that the SA materials can be transmitted by the light. Thus, we covered the end face of a fiber with a uniform ITO film using the radio frequency magnetron sputtering technology to fabricate a novel ITO SA. Using this new type of SA, single-wavelength pulses, dual-wavelength pulses, and triple-wavelength multi-pulses were achieved easily. The pulse durations of these mode-locked operations were 1.67, 6.91, and 1 ns, respectively. At the dual-wavelength mode-locked state, the fiber laser could achieve an output power of 2.91 mW and a pulse energy of 1.48 nJ. This study reveals that such a proposed film-type ITO SA has excellent nonlinear absorption properties, which can promote the application of ITO film for ultrafast photonics.

Nonlinear Optical Properties of Zirconium Diselenide and Its Ultra-Fast Modulator Application

“…Mode-locked fiber lasers have been arousing the extensive interest of many researchers due to their value in a variety of applications in the fields of basic science, fiber telecommunications, industrial materials processing, precise optical metrology, biomedical imaging, and others [1,2,3,4,5,6,7,8,9,10]. Currently, there are normally two strategies, actively mode-locked and passively mode-locked technologies, that are employed to realize the mode-locked operation in a fiber laser.…”

Palladium diselenide as a direct absorption saturable absorber for ultrafast mode-locked operations: from all anomalous dispersion to all normal dispersion

“…Besides the mentioned 2D materials, well-known non-2D crystals including QDs [6,70], nanoparticles [71][72][73] and nanorods [74] also have been used for demonstrating mode-locked fiber laser operations, especially, for obtaining conventional soliton operations. Comparison of the output characteristics of non-2D crystal-based modelocked fiber lasers and our work is depicted in Table 2.…”

Graphdiyne Saturable Absorber for Passively Q-Switched Ho3+-Doped Laser

“…In recent years, the emergence of two-dimensional (2D) materials has provided more choices and opportunities for the use of saturable absorbers (SAs) in pulsed lasers PQS solid-state lasers. They have common remarkable merits, including simple structure, compactness, easy operation, and low cost [25][26][27][28][29][30][31][32][33]. However, they also have their own disadvantages.…”