Pressure broadening and frequency shift of the

We present the results of pressure broadening and frequency shift of K D1 and D2 lines in presence of 1–4 amg of Neon gas and 1–5 amg of Krypton gas by laser absorption spectroscopy. Both pressure broadening and frequency shift are linearly related to gas density with high accuracy. The asymmetry of the absorption line shape caused by van der Waals potential was first found in the near-line wings of large density Kr in the experiment. We have also investigated the temperature dependence of the pressure broadening and frequency shift in a range of 353–403 K in Neon and 373–417 K in Krypton and compared the results of the pressure broadening and frequency shift with previous values