Characteristics of saturation spectroscopy at the Balmer-α line of atomic hydrogen in a linear magnetized plasma source

International audienceWe adopted saturation spectroscopy for observing a Doppler-free spectrum of the Balmer-α line of atomic hydrogen in a linear magnetized plasma source. The spectrum was composed of a broadband offset and many peaks which were assigned as fine-structure components of the Balmer-α line with Zeeman splitting. We examined the amplitudes of the offset and line components as functions of the pump laser power and the discharge gas pressure. The saturation parameter or the amplitude of the saturation spectrum was discussed by referring to the theory of saturation spectroscopy. In addition, the physical origin of the broadband offset component was speculated on the basis of the pressure dependence of the saturation spectrum