A mid-infrared (MIR) supercontinuum (SC) has been demonstrated in a low-loss telluride glass fiber. The doublecladding fiber, fabricated using a novel extrusion method, exhibits excellent transmission at 8-14 μm: < 10 dB/m in the range of 8-13.5 μm and 6 dB/m at 11 μm. Launched intense ultrashort pulsed with a central wavelength of 7 μm, the step-index fiber generates a MIR SC spanning from ß2.0 μm to 16 μm, for a 40-dB spectral flatness. This is a fresh experimental demonstration to reveal that telluride glass fiber can emit across the all MIR molecular fingerprint region, which is of key importance for applications such as diagnostics, gas sensing, and greenhouse CO 2 detection.
Chalcogenide glasses have the advantages of a wide transparency window (over 20 µm) and high optical nonlinearity (up to a thousand times greater than that of silica glasses), making them good candidates for mid-infrared supercontinuum generation. In this review, we describe both the history and recent developments in mid-infrared supercontinuum generation from chalcogenide fibers according to three kinds of fiber structures: step-index, microstructured and tapered fibers. We also review the coherence properties of mid-infrared supercontinuum generation and all-fiber supercontinuum sources based on chalcogenide fibers.
We report the fabrication of a novel high nonlinear fiber made of Ge-Sb-Se chalcogenide glasses with high numerical aperture (∼1.0), where the core and the cladding glasses consist of Ge15Sb25Se60 and Ge15Sb20Se65 (mol. %), respectively. The nonlinear refractive index (n2) of the core glass is 19×10-18 m2/W at 1.55 μm, and its laser-induced damage threshold under irradiation of 3.0 μm fs laser is approximately 3674 GW/cm2. By pumping a 20-cm-long fiber with a core diameter of 23 μm using 150 fs pulses at 6.0 μm, supercontinuum spanning from ∼1.8 to ∼14 μm was generated.
A tangencypoint method (TPM) is presented to derive the thickness and optical constants of chalcogenide thin films from their transmission spectra. It solves the problem of the abnormal value of thickness in the strong absorption region obtained by Swanepoel method. The accuracy of the thickness and refractive index is better than 0.5% by using this method. Moreover, comparing with Swanepoel method by using the same simulation and experimental data from the transmission spectrum, the accuracy of the thickness and refractive index obtained by the TPM is higher in the strong absorption region. Finally the dispersion and absorption coefficient of the chalcogenide films are obtained based on the experimental data of the transmission spectrum by using the TPM.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.