1.2-15.2  μm supercontinuum generation in a low-loss chalcohalide fiber pumped at a deep anomalous-dispersion region

A novel low-loss selenium-based chalcohalide fiber, with a low zero-dispersion wavelength, was prepared by an innovative preparation process. The composition optimized fiber has a wide transmission range of up to 11.5 μm, a lowest fundamental mode zero-dispersion wavelength of 4.03 μm, and a minimum optical loss of 1.12 dB/m at 6.4 μm, which provides a possibility to replace As₂S₃ and As₂Se₃ in a cascade of ZrF₄-BaF₂-LaF₃-AlF₃-NaF(ZBLAN)-As₂S₃-As₂Se₃ fiber in the practical all-fiberized supercontinuum (SC) source. Meanwhile, the broadest SC spectrum, ∼1.2 to 15.2 μm, was achieved by pumping a 12-cm-long fiber with a femtosecond laser at a deep anomalous-dispersion region. Furthermore, simulations are adopted to interpret the results as well as to demonstrate spectral evolution along the fiber. To the best of our knowledge, this is the broadest SC spectrum reported in any selenium-based chalcogenide fiber.