No abstract

Measuring states of polarizations (SOPs) is a fundamental requirement in high capacity optical communications, optical imaging, and material characterization. However, most of the existing methods focused on the assembly of spatial optical elements, making the system bulky and complex. Alternatively, the integrated methods were mainly presented by plasmonic nanostructures or metasurfaces, difficult to integrate with commonly used silicon photonic devices. For large-scale inter-chip optical interconnections, the silicon-based polarization analyzers are in demand and in its infancy. Here, a silicon-based polarization analyzer by polarization-frequency mapping is put forward. The basis vectors of polarization are mapped to two frequencies by thermally tuned phase shifters. The SOPs are retrieved from the frequency domain. The proposed polarization analyzer is demonstrated experimentally and can measure SOPs in the entire C-band. The scheme is compatible with the CMOS fabrication process, making it possible to be integrated with other silicon-based devices monolithically.

Non-Hermitian optics is a burgeoning field at the intersection of quantum physics, electrodynamics, and nanophotonics. It provides a new perspective of the role of gain and loss in optical systems. Leveraging the advanced designs inspired by non-Hermitian physics, classical optical platforms have been widely investigated to unveil novel physical concepts, such as parity-time symmetry and exceptional points, which have no counterparts in the conventional Hermitian settings. These investigations have yielded a plethora of new phenomena in optical wave scattering, optical sensing, and nonlinear optical processes. Non-Hermitian effects also have a profound impact on the lasing behaviors in the semiclassical framework of lasers, allowing for novel ways to engineer single-mode lasers, chiral laser emission, laser noise, linewidth, etc. Furthermore, over recent years, there has been increasing interest in the explorations of non-Hermitian physics in quantum optics, which addresses photon statistics, entanglement, decoherence, and quantum sensing in non-Hermitian systems. In this review, we review the most recent theoretical and experimental advances in non-Hermitian optics and photonics, covering the significant progress in both classical and quantum optics regimes.