Silicon photonic integrated devices used for nonlinear optical signal processing play a key role in ultrafast switching, computing, and modern optical communications. However, current devices suffer from limited operation speeds and low conversion efficiencies due to the intrinsically low nonlinear index of silicon. In this paper, we experimentally demonstrate enhanced optical nonlinearity in a silicon–organic hybrid slot waveguide consisting of an ultranarrow slot waveguide coated with a highly nonlinear organic material. The fabricated slot area is as narrow as 45 nm, which is, to the best of our knowledge, the narrowest slot width that has been experimentally reported in silicon slot waveguides. The nonlinear coefficient of the proposed device with a length of 3 mm is measured to be up to 1.43×106W-1km-1. Based on the nanostructure design, the conversion efficiencies of degenerate four-wave mixing showed enhancements of more than 12 dB and 5 dB compared to those measured for an identical device without the organic material and a silicon strip waveguide, respectively. As a proof of concept, all-optical canonical logic units based on the prepared device with two inputs at 40 Gb/s are analyzed. The obtained logic results showed clear temporal waveforms and wide-open eye diagrams with error-free performance, illustrating that our device has great potential for use in high-speed all-optical signal processing and high-performance computing in the nodes and terminals of optical networks.

Halide perovskites have attracted great attention due to their high color purity, high luminance yield, low non-radiative recombination rate, and solution processability. Although the external quantum efficiency of perovskite light-emitting diodes (PeLEDs) is comparable with that of the organic light-emitting diodes (OLEDs) and quantum-dots light-emitting diodes (QLEDs), the brightness is still low compared with the traditional OLEDs and QLEDs. Herein, we demonstrate high brightness and high-efficiency CsPbBr3-based PeLEDs using interface and bulk controlled nanocrystal growth of the perovskite emission layer. The interface engineering by ethanolamine and bulk engineering by polyethylene glycol led to highly crystallized and cubic-shaped perovskite nanocrystals with smooth and compact morphology. As a result, PeLEDs with a high brightness of 64756cd/m2 and an external quantum efficiency of 13.4% have been achieved.

We report an observation of the second-order correlation between twin beams generated by amplified spontaneous parametric down-conversion operating above threshold with kilowatt-level peak power, from a periodically poled LiTaO₃ crystal via a single-pass scheme. Photocurrent correlation was measured because of the bright photon streams, with raw visibility of 37.9% or 97.3% after electronic filtering. As expected in our theory, this correlation is robust and insensitive to parametric gain and detection loss, enabling important applications in optical communications, precision measurement, and nonlocal imaging.

Optical absorbers with dynamic tuning features are able to flexibly control the absorption performance, which offers a good platform for realizing optical switching, filtering, modulating, etc. Here, we propose a thermally tunable broadband absorber applying a patterned plasmonic metasurface with thermo-chromic vanadium dioxide (VO2) spacers. An actively tunable absorption bandwidth and peak resonant wavelength in the region from the near- to mid-infrared (NMIR) are simultaneously achieved with the insulating–metallic phase transition of VO2. Moreover, the scalable unit cell, which is composed of multi-width sub-cells, provides a new freedom to further manipulate (i.e., broaden or narrow) the absorption bandwidth while maintaining a high relative absorption bandwidth and efficient absorbance at the same time. For both transverse-electric and transverse-magnetic polarizations, the proposed nanostructure exhibits a high absorption over a wide angular range up to 60°. This method holds a promising potential for versatile utilizations in optical integrated devices, NMIR photodetection, thermal emitters, smart temperature control systems, and so forth.