Quantum resonant optical bistability with a narrow atomic transition: bistability phase diagram in the bad cavity regime

Abstract

We report on the observation of a novel manifestation of saturation-induced optical bistability in a resonantly pumped optical ring cavity interacting strongly with a cloud of atoms via a narrow atomic transition. The bistability emerges, above a critical pump rate, as an additional peak in the cavity’s normal mode spectrum close to atomic resonance. This third transmission peak is usually suppressed due to strong resonant absorption, but in our experiment it is visible because of the linewidth of the atomic transition being much smaller than that of the cavity, which sets the experiment into the bad-cavity regime. Relying on complete saturation of the transition, this bistability has a quantum origin and cannot be mimicked by a classical material presenting a nonlinear refraction index. The appearance of the central peak in addition to the normal modes is predicted by a semi-classical model derived from the Tavis–Cummings Hamiltonian from which we derive a bistability phase diagram that connects our observations with former work on optical bistability in the good cavity regime. The phase diagram reveals several so far unexplored bistable phases.

Matter-wave interferometry for quantum sensing

“…The additional feature presented in Figure 21 shows the appearance of non-linearity caused by bi-stability displayed in Figure 22 and obtained by numerical calculations of normal mode spectra (ramping ∆ ca ) for various detunings of the laser from atomic resonance (∆ a ), according to RIVERO (54). The horizontal cuts through the centre of the false colour images (near ∆ a = 0) represent the normal mode spectra discussed in Section 3.4.…”

“…This chapter describes an experiment and its operation aimed at quantum sensing, as cited in Chapter 1, specifically applied to gravimetry, and outlines the procedures for implementing the pulses of Ramsey-Bordé interferometer (Section 3.5 and Section 4.2). For more details on the experimental description, please refer to (53,54,(69)(70)(71).…”

“…For more details on MOT, please refer to Section 3.3.1 and previous studies conducted by the group (53,69,70). Since an auxiliary laser is a highly intense diode laser, part of its power is also used as a probe beam in experiments conducted for NMS measurements (54). Now, let us revisit Figure 13 to identifying the frequency relations used in our experiment, since the light for MOT should not have the exact frequency of the chosen transition.…”

“…The horizontal cuts through the centre of the false colour images (near ∆ a = 0) represent the normal mode spectra discussed in Section 3.4. Source: Adapted from RIVERO (54).…”