Transient studies of transparency and gain in laser-cooled rubidium lambda systems

Summary form only given. Many studies have been made of electromagnetically induced transparency (EIT) and probe gain under steady-state conditions. We have carried out experimental studies of transient effects in rubidium lambda systems in the non-adiabatic regime where the coupling field is rapidly switched on using a Pockels cell in a time that is short compared with transient time scales. Our preliminary work has confirmed predictions that the steady-state EIT is approached through damped oscillations characterised by the coupling field Rabi frequency /spl Omega//sub c/ and the spontaneous decay rate /spl Gamma/. We report results of our recent investigations into the effects of strong coupling fields conducted in several different lambda schemes in the rubidium 5S/sub 1/2/-5P/sub 3/2/ hyperfine levels in a magnetooptical trap. We also studied the effects of the initial conditions of population and optical coherence, probe absorption on uncoupled Zeeman transitions, and incoherent pumping.