分类： 光学 >> 量子光学 提交时间： 2023-02-19
摘要： The generation of squeezed light in semiconductor materials opens opportunities for building on-chip devices that are operated at the quantum level. Here we study theoretically a squeezed light source of polariton dark solitons confined in a geometric potential well of semiconductor microcavities in the strong coupling regime. We show that polariton dark solitons of odd and even parities can be created by tuning the potential depth. When driving the potential depth linearly, a bistability of solitons with the two different parities can be induced. Strong intensity squeezing is obtained near the turning point of the bistability due to the large nonlinear interaction, which can be controlled by Feshbach resonance. The phase diagram of the bistability and squeezing of the dark solitons is obtained through large scale numerical calculations. Our study contributes to the current efforts in realizing topological excitations and squeezed light sources with solid-state devices.
分类： 光学 >> 量子光学 提交时间： 2023-02-19
摘要： Topological photonics has received extensive attention from researchers because it provides brand new physical principles to manipulate light. Band topology of optical materials is characterized using the Berry phase defined by Bloch states. Until now, the criteria for experimentally probing the topological phase transition of band topology has always been relatively lacking in topological physics. Moreover, radiation topology can be aroused by the far-field polarizations of the radiating Bloch states, which is described by the Stokes phase. Although such two types of topologies are both related to Bloch states on the band structure, it is rather surprising that their development is almost independent. Here, we reveal that the phase transition of band topology can be probed by the radiation topology. We theoretically design and experimentally demonstrate such an intriguing phenomenon by constructing photonic crystals that support optical analogs of quantum spin Hall effects. The results show that the topological charge of the far-field polarization vortex changes from +1 to -2 or from -2 to +1 when the band topology changes from trivial to non-trivial, which provides a new criterion to probe the phase transition of band topology using radiation topology. Our findings not only provide an insightful understanding of band topology and radiation topology, but also can serve as a novel route to manipulate the near and far fields of light.
分类： 光学 >> 量子光学 提交时间： 2023-02-19
摘要： We propose two non-Hermitian arrays consisting of $N=2l+1$ waveguides and exhibiting parity-time ($\mathcal{PT}$) or anti-$\mathcal{PT}$ symmetry for investigating light transfer dynamics based on $N$th-order exceptional points (EPs). The $\mathcal{PT}$-symmetric array supports two $N$th-order EPs separating an unbroken and a broken phase with real and imaginary eignvalues, respectively. Light transfer dynamics in this array exhibits radically different behaviors, i.e. a unidirectional oscillation behavior in the unbroken phase, an edge-towards localization behavior in the broken phase, and a center-towards localization behavior just at $N$th-order EPs. The anti-$\mathcal{PT}$-symmetric array supports also two $N$th-order EPs separating an unbroken and a broken phase, which refer however to imaginary and real eigenvalues, respectively. Accordingly, light transfer dynamics in this array exhibits a center-towards localization behavior in the unbroken phase and an origin-centered oscillation behavior in the broken phase. These nontrivial light transfer behaviors and their controlled transitions are not viable for otherwise split lower-order EPs and depend on the underlying $SU(2)$ symmetry of spin-$l$ matrices.
点击量
待评议
点击量
下载量
评论
