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

We propose a two-step pulse observation method to enhance the frequency stability of 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 using 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.

Duke Scholars

Author Yuichiro Yano Family Medicine and Community Health