13ª Semana Integrada do Instituto de Física de São Carlos

Saturation-induced bistability in strontium atoms interacting with an optical cavity

21 de ago. de 2023 14:00

1h 30m

Salão de Eventos USP

Normal 14h00 - 15h30

Descrição

We study the interaction between a cloud of ultracold strontium atoms and the light modes of an optical ring cavity laser-pumped near a forbidden atomic transition. In our cavity 0.1 photons are enough to saturate the narrow transition, which enables us to study saturation-induced effects even on resonance without being hampered by spontaneous emission. Furthermore, with the cavity decay rate exceeding by far the rate of spontaneous emission, we are in the so-called 'bad cavity' limit. The number of interacting atoms is sufficiently high to reach the strong collective coupling regime, where the energy exchange exceeds the energy loss rate, resulting in a characteristic normal-mode splitting of the cavity transmission spectrum. When the cavity was pumped sufficiently strong, however, our measured transmission spectra revealed the presence of a third peak near the atomic resonance, which has not been observed before. We were able to explain this peak as being due to saturation induced bistability caused by a nonlinear interaction between the Autler-Townes effect and normal-mode splitting. (1-3)

Referências

1 GRIPP, J.; MIELKE, S. L.; OROZCO, L. A. Evolution of the vacuum Rabi peaks in a detuned atom cavity system. Physical Review A, v. 56, n. 4, p. 3262-3273, Oct. 1997.

2 GOTHE, H. et al. Optical bistability and nonlinear dynamics by saturation of cold Yb atoms in a cavity. Physical Review A, v. 99, n. 1, p. 013849-1-013849-5, Jan. 2019.

3 KARMSTRAND, T. et al. Unconventional saturation effects at intermediate drive in a lossy cavity coupled to few emitters. 2021. DOI: https://doi.org/10.48550/arXiv.2110.00595.