Fiber laser for on-demand mode generation in 1550 nm band

Transverse mode characteristics of a laser are related to a variety of interesting applications. An on-demand mode solid laser in the 1064 nm band was proposed previously. In this paper, we provide a fiber laser for on-demand modes in the 1550 nm band to prescribe the pure and high-quality emission of a higher-order transverse laser mode, based on a simple construction with one spatial light modulator（SLM） and a single-mode erbium-doped fiber（SM-EDF）. The SLM is designated to generate the desired higher-order mode and separate the higher-order mode and the fundamental mode. The fundamental mode oscillates in the fiber ring laser, and therefore the SM-EDF can be pumped with a single-mode 980 nm laser, no matter what higher-order mode is prescribed.In this proof-of-principle experiment, high-quality higher-order modes are observed from LP01 to LP105.Stable emission and real-time switching between modes can be easily realized by altering the phase on the SLM. In addition, the propagation of the LP01, LP11, LP21, and LP02 modes from the fiber laser is also demonstrated in a four-mode few-mode fiber.