One Is Not Enough: Intra-Cavity Spectroscopy with Multi-Mode Lasers

Quantitative Intracavity Laser Spectroscopy Measurements with a Ti:sapphire Laser: Absorption Intensities for Water Vapor Lines in the 790–800 nm Region

“…Equation [1] is the Beer-Lambert relationship for ILS with the effective absorption path length (L eff ) given by {(l/L) ⅐ c ⅐ t g }. Two procedures that were employed to determine the intensities of absorption lines were described previously (25,26).…”

“…During the cavity buildup and oscillation period, the absorption strength appears to increase in a linear fashion with generation time. There is, however, an offset value associated with the time taken to reach population 1 To whom correspondence should be addressed.…”

“…Intracavity laser spectroscopy (1,2) and cavity ring-down spectroscopy (pulsed as well as cw versions) (3,4) are techniques that provide enhanced sensitivity for detecting absorption. To derive quantitative parameters for absorbing species using such methodologies, it is necessary to examine under what circumstances accurate data for absorbers can be obtained with a specific type of laser system.…”

Cavity-based absorption spectroscopy techniques

“…By contrast, ICLAS entails placing the absorbing medium inside the cavity of a coherent light source (such as a laser or an optical parametric oscillator). There are several informative reviews of ICLAS and its applications (Harris, 1984;Atkinson, 1986Atkinson, , 2002Toschek and Baev, 1987;Baev et al , 1999;Romanini, 1999). A selection of additional publications concerns ICLAS instrumentation (H ä nsch et al , 1972;Brunner et al , 1979;Harris and Weiner, 1981;Garnache et al , 2000;Scherer et al , 2009;Ueda et al , 2012) and its applications, e.g., in studies of transient molecular species (Sheehy and Steinfeld, 2005) and in high-resolution molecular spectroscopy (Oka, 1982;Scherer et al , 1983).…”

<title>Gas sensors based on fiber laser intracavity spectroscopy (FLICS)</title>

“…Several laser systems have been used successfully in the detection of absorbers by means of Laser Intra-cavity Spectroscopy (LICS), and different theoretical descriptions of this measurement method can be found in the literature [1,2]. In the simplest analysis, with high reflectivity mirrors and for the case in which the laser line width is narrower than the absorption feature ofthe gas, there will be many passes through the cavity, so the effective length ofthe absorption cell is increased.…”