Two-step pulse observation for Raman-Ramsey coherent population trapping atomic clocks

الأصل · EN

We propose a two-step pulse observation method to enhance frequency stability for coherent population trapping (CPT) atomic clocks. The proposed method is a Raman-Ramsey scheme with low light intensity at resonance observation, and provides a Ramsey-CPT resonance with both reduced frequency sensitivity to the light intensity and a high signal-to-noise ratio by reducing the repumping into a steady dark state. The resonance characteristics were calculated based on density matrix analysis of a Λ-type three level system that was modeled on the ¹³³Cs-D₁ line, and the characteristics were also measured using a vertical-cavity surface-emitting laser and a Cs vapor cell.