Two-Photon Raman Gain in a Laser Driven Potassium Vapor

Atomic systems that display a linear or weakly nonlinear interaction with light, such as that occurring in typical optical ampliÞers and lasers, are well known and well understood. However, when the interaction between light and matter becomes highly nonlinear and the light and matter strongly couple, the systems become much more difficult to understand both theoretically and experimen-tally. One example of a strongly coupled, highly nonlinear system is the two-photon laser that is based on the two-photon stimulated emission process. This laser has intrigued theorists and experimentalists alike over the past three decades because of the challenges in explaining the interactions taking place in the device as well as the possibilities for novel and potentially useful be-havior. Research concerning two-photon lasers has been hindered, however, by the difficulties in constructing such a laser. Most two-photon gain media prove unsuitable due to small gain and the occurrence of destructive competin