Low-cost resonant cavity Raman gas probe for multi-gas detection J. Thorstensen, K. H. Haugholt, A. Ferber, K. A. H. Bakke and J. Tschudi J. Eur. Opt. Soc.-Rapid Publ., 9 (2014) 14054 Published online: 16 December 2014 DOI: 10.2971/jeos.2014.14054