Incoherent Gain-Assisted Ring Enhanced Gas Absorption Spectroscopy Selim, Mahmoud A. ; Adib, George A. ; Sabry, Yasser M. ; Khalil, Diaa Abstract Publication: IEEE Journal of Quantum Electronics Pub Date: February 2019 DOI: 10.1109/JQE.2018.2890214 Bibcode: 2019IJQE...5590214S