Studies of electromagnetically induced transparency in thallium vapor and possible utility for measuring atomic parity nonconservation

Motivated by the potential use of electromagnetically induced transparency (EIT) to measure atomic parity nonconservation (PNC), we have studied EIT and associated optical rotation for a three-level system in thallium vapor. EIT allows sub-Doppler resolution of the 6P_1/2→6P_3/2 mixed magnetic dipole, electric quadrupole transition at 1.28µm when 0.535−µm radiation acts on the 6P_3/2→7S_1/2 transition. Our measurements include rotation due to electromagnetically induced birefringence and Faraday rotation perturbed by EIT. We also identify a new method for determining the amplitude ratio E2/M1 for the 1.28−µm transition. The possible advantages of an EIT technique for measuring atomic PNC are discussed in the context of our results.