Precision Spectroscopy of Yb atoms and Design of linear ion trap for confining Yb ions

Abstract

This thesis presents a study of two important areas of atomic and quantum technolo- gies: precision spectroscopy of neutral Ytterbium (Yb) atoms and the simulation of ion confinement using radio-frequency ion traps. The work focuses on overcoming lim- itations associated with Doppler broadening in spectroscopy and static confinement of charged particles. High-resolution spectroscopy of the 1S0 → 1P1 transition of neutral Ytterbium at 398.911 nm was investigated using saturation absorption spectroscopy (SAS). Conven- tional absorption spectroscopy measurements produced Doppler-broadened Gaussian profiles originating from the thermal velocity distribution of atoms, limiting the abil- ity to resolve fine spectral structures. To overcome this limitation, a pump–probe configuration employing counter-propagating laser beams was implemented to isolate atoms with nearly zero velocity along the laser propagation axis, enabling the ob- servation of narrow Doppler-free spectral features. Measurements were performed at different pump powers to investigate the effect of power broadening and its influence on spectral linewidth. Although a fully resolved Lamb dip could not be conclusively obtained, the experimental setup was successfully developed and optimized, providing an important foundation for future precision measurements. In addition, a complete optical apparatus for Cross-Beam Saturated Absorption Spectroscopy (CBSAS) was designed and assembled to reduce power broadening effects and enable improved fre- quency measurements in future studies. The second part of this work investigates ion confinement using radio-frequency quadrupole ion traps. Since stable three-dimensional confinement cannot be achieved using static electric fields due to the constraints imposed by Laplace’s equation, dy- namic confinement through time-varying fields was studied. The motion of trapped ions was analyzed through the Mathieu equations and simulated numerically using the Runge–Kutta method. Stable trapping conditions were examined for different stability parameters, and bounded ion trajectories were observed within specific sta- bility regions. The simulations demonstrate the coexistence of slow secular motion and rapid micromotion in trapped-ion dynamics. The results also indicate that prac- tical electrode geometries can achieve stable confinement despite deviations from ideal quadrupole fields. Overall, this work establishes both an experimental and computational framework for future investigations in high-resolution spectroscopy and trapped-ion systems, with potential applications in atomic clocks, laser cooling, quantum information processing, and precision quantum technologies