Intracavity absorption spectroscopy with a tunable multimode traveling-wave ring Ti:sapphire laser

摘要

A tunable multimode unidirectional traveling-wave Ti:sapphire laser was developed to measure in situ the atmospheric absorption spectra using intracavity absorption spectroscopy. The effective absorption path length was 2100 km. O_(2) and H_(2)O vapor lines in atmosphere with absorption coefficients of 10~(-6)-10~(-8) cm~(-1) were measured with uncertainties <5percent, and the absorption coefficients were in agreement with those estimated from the HITRAN database. By tuning the wavelength, a weak absorption line with an absorption coefficient of 10~(-9) cm~(-1) was measured with a sensitivity of 2 X 10~(-10) cm~(-1). The sensitivity was limited by the residual parasitic variation that appeared in the spectrum.