Two photon time-resolved optogalvanic signals of Neon

Illumination of a gas discharge with radiation at a wavelength corresponding to an atomic transition of a species in the discharge causes perturbation to the steady state population of two or more levels. This, in turn, causes a change in the electrical properties of the discharge. This process is known as optogalvanic effect which has been found to be an excellent tool in the field of spectroscopy. Han et al. developed a simple theoretical model to understand the physics of the time-resolved optogalvanic signals [1,2]. Using this model, the decay rates of various transitions resulting from the excitation of neon’s first metastable level was determined. Recently, Piracha et al. have reported a study on the time-resolved optogalvanic spectra of neon and krypton using the Han et al. model [3]. They concluded that the electron collisional ionization was the dominant process in the characterization of the optogalvanic signal. We present new studies on the temporal evolution of the two photon laser optogalvanic signals of neon using commercial hollow cathode lamps in conjunction with a Nd:YAG pumped Dye laser system.