Stable single light bullets and vortices and their active control in cold Rydberg gases

Abstract

Realizing single light bullets and vortices that are stable in high dimensions is a long-standing goal in the study of nonlinear optical physics. On the other hand, the storage and retrieval of such stable high dimensional optical pulses may offer a variety of applications. Here we present a scheme to generate such optical pulses in a cold Rydberg atomic gas. By virtue of electromagnetically induced transparency, strong, long-range atom-atom interaction in Rydberg states is mapped to light fields, resulting in a giant, fast-responding nonlocal Kerr nonlinearity and the formation of light bullets and vortices carrying orbital angular momenta, which have extremely low generation power, very slow propagation velocity, and can stably propagate, with the stability provided by the combination of local and the nonlocal Kerr nonlinearities. We demonstrate that the light bullets and vortices obtained can be stored and retrieved in the system with high efficiency and fidelity.Our study provides a new route for manipulating high-dimensional nonlinear optical processes via the controlled optical nonlinearities in cold Rydberg gases.

Structural phase transitions of optical patterns in atomic gases with microwave-controlled Rydberg interactions

“…Generalizing the approach developed in Refs. [86][87][88][89], where MB equations for Rydberg atomic gases without microwave dressing are solved beyond mean-field approximation in a self-consistent and effective way, we can obtain the solutions of the Bloch Eq. (3) using the perturbation expansion up to third-order approximation.…”

“…nloc are local and nonlocal third-order nonlinear (Kerr) susceptibilities, originated respectively from non-zero two-photon detuning (i.e. ∆ 3 = 0) [86][87][88][89][90][91]) and from the Rydberg-Rydberg interaction in the system. Expressions of χ (1) , χ (3) loc , and χ (3) nloc are given in Appendix B; see Eqs.…”

“…with r ⊥ = (x, y), d 2 r = dx dy . The third and forth terms on the left hand side of this equation describe two types of self-phase modulations of the probe field, contributed respectively by the local Kerr nonlinearity (originated from non-zero two-photon detuning (i.e., ∆ 3 = 0) [86][87][88][89][90][91]) and the nonlocal Kerr nonlinearity (originated from the Rydberg-Rydberg interaction). In the integral of the forth term of the NNLS equation, G is a reduced nonlinear response function, taking the form For the convenience of later discussions and numerical calculations, we rewrite the 3D NNLS Eq.…”

Manipulation of a weak signal pulse by optical soliton via double electromagnetically induced transparency

“…The disadvantages mentioned above can be overcome by the discovery of electromagnetically induced transparency (EIT) in a resonant atomic system at very low light level [16]. Through the giant enhancement of self-Kerr and cross-Kerr nonlinearities induced by EIT, there are many interesting researches paying attention to numerous nonlinear optical progresses, including temporal (spatial) optical solitons [17][18][19], Manakov/ Thirring vector solitons [20][21][22][23][24][25], high-dimensional spatiotemporal optical solitons [26][27][28][29][30], efficient multiwave mixing [31], the bistable state [32], and so on. In addition, different from the mechanism of Manakov/Thirring model, trapping light by light here is that a soliton pulse formed by self-phase modulation (SPM) offers an external potential to a weak laser light pulse through CPM.…”

“…To generate such LBs, high light-intensity and ultrashort laser pulses are generally needed, and they are not easy to manipulate actively. Although the (3+1)D LBs can be formed in EIT-based system with low generation power [26][27][28][29][30], all of them only consider isolated LB and no interaction between LBs. A weak signal pulse trapped by a probe soliton has been explored deeply in a tripod-type atomic system via double EIT [33,34], but no (3+1)D LBs are touched.…”