Direction-dependent propagation of high-power femtosecond pulses through a large-mode-area tapered fiber

Abstract

We propose a design of a large-mode-area W-fiber tapered fiber for the direction-dependent propagation of high-power femtosecond pulses at 1550 nm wavelength. In the down-tapered case (forward propagation), the fiber supports propagation of a 40 kW, 85 fs Gaussian pulse with small variations in the pulse shape over a 5 m distance. In the up-tapered (backward propagation) case, the pulse significantly disperses to nearly 1000 fs. Such a fiber would be useful for delivering ultrashort high-peak-power pulses while simultaneously working as an isolator. © 2018 Optical Society of America.