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

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 mu 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 mu 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.