Wavelength-agile source based on a potassium atomic vapor cell and application for absorption spectroscopy of iodine

Output from a mode-locked Ti:Sapphire laser was transmitted through a cell containing atomic potassium vapor. Because the group velocity dispersion near the D1 resonance varies strongly with wavelength, a chirped pulse was emitted from the cell. This chirp was treated as a wavelength-agile source and was applied for a high-resolution measurement of the R(101)A3Π1u-X1Σg+(0,13) iodine absorption feature. The agile measurement was compared to one obtained using an external cavity diode laser. The characteristics of the potassium vapor cell and the associated effects on the transmitted chirp were examined in detail. Extensions of this general approach to practical applications are discussed.