Radial distribution gain at 633 nm in a He-Ne RF-excited small bore discharge

Devices as Large Ring Laser Gyroscopes (RLG) for fundamental physics and geophysics investigation are currently run by means of RF power supply systems. This is not the standard method to supply a gas laser, that typically is powered with a DC system. In literature RF power supply lasers have been studied several years ago, and to correctly understand the behaviour of devices as RLG a more detailed study has been pursued. Detailed study of the radial distribution of the optical gain of an He-Ne discharge cell in function of gas pressure and RF power supply will be illustrated, discussed and compared with existing literature. The presented analysis demonstrates that it is possible to optimize the RLG operation with a proper choice of gas pressure and power level of the RF power supply. Accordingly we have been able to establish transversal and longitudinal single-mode operation our prototype GP2.