This paper presents a study of two commercial hollow-cathode lamps (HCLs) with the intention
of demonstrating different phenomena in gas discharges. The optogalvanic effect in both HCLs is
produced by a laser diode radiated at the wavelength that corresponds to neon transition 1s 2 –2p 2
at 659.89 nm. The voltage–current characteristics of the lamps are explained using a classical
theory of hollow-cathode discharge, while the optogalvanic signal is treated as a small perturbation
of the discharge current. For certain values of voltage self-sustained current oscillations are
observed in one of the HCLs. In the same HCL laser-induced optogalvanic dumped oscillations are
detected. A phenomenological model that includes the effective circuit parameters of the discharge
is used to explain the oscillation characteristics.