Stark Modulation Spectroscopy in the Visible Region

The idea of Stark modulation spectroscopy in the visible region is a natural extension of the classical technique which has been used for many years in microwave spectroscopy and recently in infrared spectroscopy. By means of the Stark modulation technique very high sensitivities can be achieved and, at the same time, important clues for the assignment of absorption lines are obtainable. Although the potential usefulness of this technique using a cw dye laser as a light source has been demonstrated in a previous work [1] on the NO2 spectrum, little other application of the method to visible spectra has been reported. In the present work selected parts of the visible absorption spectra of two diatomic molecules, ICl and I2, are reexamined by Stark modulation spectroscopy.