Note

High-sensitivity CW-cavity ringdown spectroscopy of 12CO2 near 1.5μm

“…Excluding the 40013-10001 band, we obtain an average difference of À4 · 10 À3 and an RMS of 1.4 · 10 À2 cm À1 confirming that the line positions of [2] are both less accurate and overestimated. As previously discussed in [10], this shift has the tendency to increase with the wavenumber and reaches a value of 0.013 cm À1 in the region of the 2m 1 + 3m 3 triad near 9500 cm À1 [7]. For completeness, we mention that a discussion of the rovibrational parameters previously obtained by Chou et al [5] and Maillard et al [4] is included in [6] and not reconsidered in details here.…”

“…In particular, we have investigated the 12 CO 2 overtone bands above 9000 cm À1 by intracavity laser absorption spectroscopy (ICLAS) (see [7] and the review of the observed transitions above 10 000 cm À1 included in [8]). In the present work, we used the CW-cavity ringdown spectroscopy (CW-CRDS) setup based on fibered DFB lasers which was recently developed in Grenoble.…”

High sensitivity cw-cavity ringdown and Fourier transform absorption spectroscopies of 13CO2

“…The parameters for the ground level were taken from [31]. The band origin, m 0 , was obtained from the variation of the vibrational term values: spectra in the region of the 2m 1 þ 3m 3 triad near 9500 cm À1 [4]. The good agreement observed in the 4000-5000 cm À1 region is not fortuitous as CO lines in this region were used to correct the Doppler shift affecting Venus data [2].…”

“…In particular, we have applied to the 12 CO 2 species, the intracavity laser absorption spectroscopy (ICLAS) technique above 9000 cm À1 (see [4] and the review of the observed transitions above 10 000 cm À1 given in [5]). For instance, compared to laboratory measurements around 1 lm [4], a shift of the order of 10 À2 cm À1 was evidenced in the wavenumber calibration of 12 CO 2 bands observed in the Venus spectra, allowing for a significant improvement of the consistency of the analysis of the atmospheric spectrum in this spectral region [6]. In the present work, to fully characterize the spectrum near 1.5 lm corresponding to an atmospheric transparency window, the spectrum has been recorded by using cw-cavity ringdown spectroscopy (CRDS).…”

Observation by ICLAS VeCSEL technique, and rotational analysis, of the ΔvGeH=5 stretching vibrational overtone of H370GeD

“…Quantum well semiconductor structures have been used as amplifying media giving access to the 8800-10 100 cm À1 region, not accessible by ICLAS-Ti:Sapphire, and applied recently to the spectroscopy of CO 2 [14], N 2 O [13,15], H 2 S [16], OCS [17], HDO [18], and H 2 O [19]. Note that, in spite of its very high sensitivity, ICLAS VeCSEL shows some characteristics related to its particular laser dynamics which may lead to distorted line profiles and hamper its use for absolute intensity measurements [20].…”