Observation of Raman Resonance of a Probe in a Rb Cell Added to an Ethane-Rb Laser for Realizing a Superluminal Laser

We report sub-natural linewidth Raman resonance for a probe applied to an auxiliary Rb cell added to an Ethane-Rb laser as a key step towards realizing a superluminal ring laser for ultrasensitive gyroscopy and accelerometry.