1.9 octave supercontinuum generation in a As2S3 step-index fiber driven by mid-IR OPCPA.

Using a 3.1-µm optical parametric chirped-pulse amplifier (OPCPA), we generate a supercontinuum in a step-index chalcogenide fiber that spans from 1.6 to 5.9 µm at the -20 dB points. The rugged step-index geometry allows for long-term operation, while the spectral bandwidth is limited by the transmission of the As2S3 fiber.