Compact supercontinuum sources based on tellurite suspended core fibers for absorption spectroscopy beyond 2μm

We present the experimental development of two compact supercontinuum laser sources based on tellurite suspended core fibers with and without tapering post-processing. The pumping scheme makes use of commercially-available nJ-level femtosecond and picosecond fiber lasers at 1.56 and 2.06 μ m respectively. The resulting spectral broadening that occurs in a few tens-of-centimeters of tellurite fiber allows coverage of the convenient molecular fingerprint region between 2 and 3 μ m. It is then exploited in a proof-of-principle experiment for methane spectroscopy measurements in the mid-infrared by means of the supercontinuum absorption spectroscopy technique. Experimental results are in fairly good agreement with both numerical simulations of supercontinuum generation and spectroscopic predictions of the HITRAN database.