@article{ISI:000290852800014,
  title = {Actively coupled cavity ringdown spectroscopy with low-power broadband sources},
  journal = {OPTICS EXPRESS},
  abstract = {We demonstrate a coupling scheme for cavity enhanced absorption spectroscopy that makes use of an intracavity acousto-optical modulator to actively switch light into (and out of) a resonator. This allows cavity ringdown spectroscopy (CRDS) to be implemented with broadband nonlaser light sources with spectral power densities of less than 30 mu W/nm. Although the acousto-optical element reduces the ultimate detection limit by introducing additional losses, it permits absorptivities to be measured with a high dynamic range, especially in lossy environments. Absorption measurements for the forbidden transition of gaseous oxygen in air at similar to 760nm are presented using a low-coherence cw-superluminescent diode. The same setup was electronically configured to cover absorption losses from 1.8 x 10(-8)cm(-1) to 7.5\% per roundtrip. This could be of interest in process analytical applications. (C) 2011 Optical Society of America},
  volume = {19},
  number = {11},
  pages = {10164-10173},
  year = {2011},
  slug = {isi-000290852800014},
  author = {Petermann, Christian and Fischer, Peer}
}