The feasibility of carrier-envelope phase (CEP) detection using few-cycle pulse pairs is numerically analyzed in a two-level system. Much lower power requirement is demonstrated in comparison with single-pulse schemes.
Get PDF Email Share Share with Facebook Tweet This Post on reddit Share with LinkedIn Add to CiteULike Add to Mendeley Add to BibSonomy Get Citation Copy Citation Text B. Zeng and L. Duan, "Carrier-Envelope Phase-Dependent Coherence in Two-Level Systems Interacting with Few-Cycle Pulse Pairs," in Conference on Lasers and Electro-Optics, OSA Technical Digest (online) (Optica Publishing Group, 2017), paper JTh2A.16. Export Citation BibTex Endnote (RIS) HTML Plain Text Citation alert Save article
The response of a two-level system to a few-cycle pulse pair has been investigated with a special focus on the relation between population inversion and the carrier-envelope phases (CEPs) of the two pulses. The goal is to explore possible schemes of coherent control based on sequential ultrafast pulses. Simulation results indicate a close CEP-inversion relation, which stems from the coherent nature of the interaction. The impact of the pulse amplitudes is evaluated and is shown to create weak-field and strong-field interaction regions with drastically different characteristics. The important role of carrier-wave Rabi flopping in defining these characteristics is also analyzed. Finally, advantages of the method and experimental realization are discussed.
We investigate numerically with Hylleraas coordinates the frequency dependence of the carrier-envelope phase (CEP) effect on bound-bound transitions of helium induced by an ultrashort laser pulse of a few cycles. We find that the CEP effect is very sensitive to the carrier frequency of the laser pulse, occurring regularly even at far-off-resonance frequencies. By analyzing a two-level model, we find that the CEP effect can be attributed to the quantum interference between neighboring multiphoton transition pathways, which is made possible by the broadened spectrum of the ultrashort laser pulse. A general picture is developed along this line to understand the sensitivity of the CEP effect to the laser's carrier frequency. Multilevel influence on the CEP effect is also discussed.