Sensitivity of a helium-neon laser utilizing 3s2–2p4 and 3s2–3p4 coupled transitions in neon to discharge current fluctuations

A calculation is reported of the sensitivity of the intensity of λ = 0.63μ, radiation, emitted from a helium-neon laser excited by a dc discharge, to discharge current fluctuations. The influence of simultaneous emission of λ = 3.39μ. radiation (due to a coupled transition) on this sensitivity if found for a wide range of discharge currents and current-fluctuation frequencies. It is shown that fluctuations of the intensity of the λ = 0.63μ radiation, resulting from the corresponding fluctuations of the discharge current, can be reduced considerably not only at low (0–1 kHz) fluctuation frequencies but also at a "resonance'' frequency which amounts to a few tens of kilohertz. The results of these calculations are confirmed by experimental results obtained in the frequency range 0–100 kHz.