Three octave visible to mid-infrared supercontinuum generation seeded by multimode silica fiber pumped at 1064 nm

Hyperspectral spectroscopy requires light sources with wide spectral ranges from the visible to the mid-infrared. Here, we demonstrate the first fiber-based mid-infrared supercontin-uum covering three octaves of frequency by leveraging 1-& mu;m laser technology. The process consists in spectral broadening of a 1064-nm pump toward 0.48-2.5 & mu;m in a graded-index multimode fiber, followed by a fluoro-indate fiber used to reach deeper into the near infrared (4.3 & mu;m). Finally, an arsenic selenide chalcogenide fiber allows us to reach the 6-& mu;m wavelength region, providing a 0.75-6-& mu;m supercon-tinuum. We illustrate the potential of this light source by recording mid-infrared absorption spectra of organic com-pounds. & COPY; 2023 Optica Publishing Group