2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/139233We evaluate the use of Coherent Population Trapping (CPT) excited with parallely polarized laser fields in vapour cell atomic clocks. We study the resonance shape, the discriminator slope and signal-to-noise ratio as a function of relevant parameters such as the laser frequency detuning and the applied magnetic field. We show that a stability of $6 \cdot 10^{-12}$ $τ^{-1/2}$ may be reached in a compact system using a modulated VCSEL.9 pages, 5 figures, submittedAtomic Physicstext