Cascaded Mid-IR Supercontinuum generation in chalcogenide microstructured optical fibers from 2 to 10 μm

Abstract

Compared to oxide based glasses, vitreous materials composed of chalcogen elements (S, Se, Te) show large transparency windows in the infrared. Indeed, chalcogenide fibers can be transparent from the visible up to 12-15 μm, depending on their compositions. The IR signatures of most molecules, including biomolecules, are located in this spectral domain, which allows in situ, non-invasive and real-time detection of gaz or organics molecules. Indeed, chalcogenide glasses can present a high non-linear coefficient (n2), 100 to 1000 times larger than for silica glass, depending on the composition. An original way to obtain fibers is to design microstructured optical fibers (MOFs). These fibers present unique optical properties thanks to the high degree of freedom in the design of their geometrical structure. Various chalcogenide MOFs operating in the mid-IR range have been elaborated in order to associate the high nonlinear properties of these glasses and the original MOF properties. Different glass compositions and different designs have been achieved depending on the intended application. Indeed, chalcogenide MOFs might lead to new devices with unique optical properties in the Mid-IR domain like multimode or endlessly single mode transmission of light, small or large mode area fibers, non-linear properties for wavelength conversion or generation of supercontinuum sources. In this work, a supercontinuum from 2 to 10 μm, with an average power of 15mW, has been obtained in a chalcogenide MOF by pumping with a supercontinuum generated in a fluoride fiber.