NOISE-FREE PARAMETRIC ENERGY MULTIPLICATION FOR FREQUENCY MEASUREMENTS OF AN ANHARMONIC MONO-ION OSCILLATOR

We have used a mono-ion oscillator to demonstrate the usefulness of a spectroscopic technique for achieving high-resolution frequency measur ements in the presence of anharmonicity. The technique uses a noise-fr ee parametric process to amplify a weakly pre-excited oscillator that allows one to reduce anharmonic frequency shift and at the same time t o detect the resonance signal with large amplitude. In our initial exp eriments using the parametric process, 100 times narrower spectral lin es have been obtained. The technique is potentially useful in such hig h-precision experiments as the electron g-2 measurement and the ion ma ss spectroscopy in Penning traps. The possibility of using the paramet ric process to detect the n=0-->n=1 transition of the cyclotron motion in geonium is also discussed.