With elongated cavity length, a 317 kHz low-repetition-rate rectangular pulse was demonstrated in an all-normal dispersion mode-locked (ML) ytterbium-doped fiber laser (YDFL) based on the nonlinear polarization evolution technique. As the pump power increased, the duration of the rectangular pulse broadened linearly without wave-breaking. At a maximum pump power of 240 mW, a rectangular pulse with a duration of 20.5 ns and highest pulse energy of 182 nJ was produced. Through an Yb 3+ -doped fiber amplifier with 4 W pump power, the energy of the rectangular pulse was further amplified up to 2.28 µJ. The duration of the rectangular pulse remained constant as the pump energy increased and revealed no pulse distortion under the maximum output energy.
Near-infrared supercontinnum (SC) generation, accompanied with several emission bands at visible and ultraviolet, is experimentally investigated in an all-fiber single-mode Yb(3+)-doped silica fiber MOPA. The seed is an all-normal-dispersion mode-locked Yb(3+)-doped single-mode fiber laser using a nonlinear polarization evolution mechanism. With the pump power of several hundreds of milliwatts, SC spanning of 1010 nm to 1600 nm was generated in a 20-m single-mode germano-zirconia-silica Yb(3+)-doped fiber amplifier. The intensive nonlinear effects, namely stimulated Raman scattering, four wave mixing, and self-phase modulation, enable the SC generation in the small-core fiber amplifier without the use of photonic crystal fibers or tapered fibers. Such a compact and cost-effective SC generation system enables applications in optical coherent tomography, optical metrology, and nonlinear microscopy.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.