Coherent ultrabroad orbital angular momentum supercontinuum generation in an AsSe2-As2S5 microstructured fiber with all-normal dispersion

We design and simulate a hollow AsSe2-As2S5 microstructured fiber surrounded by air holes with nearly-zero flattened all-normal dispersion profile. Simulation results show that the coherent first-order orbital angular momentum (OAM1,1) supercontinuum (SC) spectrum extending from 1.3 to 11 μm at −40 dB level, which can be achieved by pumping a chirp-free hyperbolic secant pulse with 100 fs pulse duration and 20 kW peak power at the wavelength of 6 μm into an 11 mm proposed fiber. Due to the flexible controllability for chromatic dispersion of this fiber, several coherent SC spectra generated by different OAM modes are analyzed. •A novel fiber is proposed which can achieve HE2,1 dispersion from −13 to −0.7 ps/nm/km over 3.3–8.6μm.•A method to get nearly-zero flattened dispersion of different high-order modes is summarized.•Several orbital angular momentum supercontinuum spectra spanning from 1.3 to 11μm at −40 dB are obtained.