Broadband high-power mid-IR supercontinuum generation in tapered chalcogenide step-index optical fiber

Abstract

We report a design, analysis, and numerical modeling of a tapered chalcogenide step-index fiber for broadband high-power mid-infrared supercontinuum extending from the 1.5–14.5 µm molecular ‘fingerprint region’. The reported tapered chalcogenide fiber structure is able to generate a broadband supercontinuum spectrum with output average power of 82 mW (27.7 mW for the wavelengths >5 µm) when it is pumped with 200 fs laser pulses with a repetition rate of 76 MHz and average power of 200 mW at 3.5 µm. Such a bright and broadband mid-infrared supercontinuum light source covering both the 3–5 µm and 8–13 µm atmospheric windows and most of the molecular fingerprint spectral region has practical applications in various fields, including mid-infrared spectroscopy, imaging, and biomedical diagnostics.