INDUCED-DICHROISM-EXCITED ATOMIC LINE FILTER AT 532 NM

The operation of a narrow-linewidth optical filter based on the 4P(1/2 )-->8S(1/2) excited-state transition in potassium vapor is reported. T he 4P(1/2) state is excited by a circularly polarized, 769.9-nm, 10-ns pulse from a dye laser. A linearly polarized, time-sequenced, and spa tially overlapped probe pulse at 532.33 nm completes the transition to the 8S(1/2) state. The peak filter transmission is similar to 40% wit h a bandwidth of less than 4 GHz. Corroborative experimental results s uggest that the rotation of probe-pulse polarization by an induced cir cular birefringence is the dominant mechanism behind the filter operat ion.