Small organic molecules (SOMs) with fascinating chiroptical properties have received much attention for their potential applications in photoelectric and biological devices. As an important research tool, circularly polarized luminescence (CPL) provides information about the chiral structures of these molecules in their excited state, and has been an active area of research. With the development of the commercially available CPL instrumentation, currently, more and more research groups have attempted to enhance the CPL parameters (i.e., quantum yield and dissymmetry factor) of the chiral SOMs from all aspects. This review summarizes the latest five years progresses in research on the experimental techniques and theoretical calculations of CPL emitted from SOMs, as well as forecasting its trend of development.

Metasurfaces, with an outstanding capacity to manipulate optical properties, have opened up a new avenue for realizing ultra-compact image displays, as exemplified by near-field nanoprinting images and far-field holographic images. Integrating these two functionalities into a single metasurface can significantly enhance functionality and increase information capacity. However, current studies have faced limitations in simultaneously achieving multifunctionality, dynamic tunability, and effective linear and circular polarization channel decoupling with a simple structure, often resulting in severely constrained information capacity and functional application. In this paper, we propose a quad-channel metasurface for dynamic image display based on a single-size nanostructure, using the polarization decoupling properties of exceptional points (EPs), the degeneracy of Malus’ law, and the phase-transition characteristics of vanadium dioxide (VO₂). In VO₂’s insulating phase, Malus’ law degeneracy decouples non-orthogonal linear polarization channels, enabling dual-channel near-field nanoprinting. Upon transitioning to VO₂’s metallic phase, polarization decoupling at EPs separates orthogonal circular polarization channels, enabling dual-channel far-field holography. As proof-of-concept, we simulated a single-sized nanostructure metasurface achieving simultaneous dual-channel near-field nanoprinting and far-field holographic display. This approach offers what we believe to be a novel paradigm for developing multifunctional metasurfaces, holding great promise for applications in information encryption and multichannel dynamic displays.

We have investigated numerically toroidal dipolar excitation at optical frequency in metamaterials whose unit cell consists of three identical Ag nanodisks and a SiO₂spacer on Ag substrate. The near-field plasmon hybridization between individual Ag nanodisks and substrate forms three magnetic dipolar resonances, at normal incidence of plane electromagnetic waves. The strong coupling among three magnetic dipolar resonances leads to the toroidal dipolar excitation, when space-inversion symmetry is broke along the polarization direction of incident light. The influences of some geometrical parameters on the resonance frequency and the excitation strength of toroidal dipolar mode are studied in detail. The radiated power from toroidal dipole is also compared with that from conventional electric and magnetic multipoles.

Bidirectional nanoprinting, has received significant attention in image display and on-chip integration, due to its superior advantages. By manipulating the amplitude in a narrow- or broad-band wavelength range of forward and backward incident light, different spatially varied intensities or color distributions can be generated on the structure plane. However, the current scheme cannot fully decouple the bidirectional light intensity due to the limitation of design degree of freedom, and it would hinder the development of asymmetric photonic devices. In this paper, we propose and demonstrate bidirectional nanoprinting based on an all-dielectric bilayer metasurface, which can independently control the intensity of forward and backward incident light, resulting in two different continuous grayscale meta-image displaying in the visible region. This asymmetric but still bidirectional optical response is introduced by stacking two layers of nanostructures with different functionality in space, in which the first- and second-layer nanostructures act as a half-wave plate and a polarizer, respectively. Interestingly, these bidirectional nanoprinting metasurfaces have flexible working modes and may bring great convenience for practical applications. Specifically, two different meta-images generated by a bidirectional nanoprinting metasurface can be displayed not only on two sides of the metasurface (working mode in transmission or reflection), but on the same side due to the forward transmitted light and backward reflected light also having asymmetric optical properties. Similar phenomena also exist for forward reflected light and backward transmitted light. Our work extremely expands the design freedom for metasurface devices and may play a significant role in the field of optical display, information multiplexing, etc.

A reflective fiber temperature sensor system based on the ZnO thin film is proposed. The transmittance spectra and temperature dependent optical property of the sensing head with ZnO thin film is investigated theoretically and experimentally, and the temperature resolution of ∼1 °C is obtained in the temperature region of 300–773 K. The temperature sensing system is only related to the wavelength shift of transmittance spectra, and has a high stability without depending on the incident light intensity. This research results also indicate a fiber optical sensor with a broad temperature measurement range (10–1800 K) can be gained as a promising temperature sensing device, and can be applied into some extremely environments, such as aircraft, nuclear power station and power transmission system, and so on.

The bandwidth-tunable absorption enhancement of monolayer graphene is theoretically studied in the near-infrared wavelengths. The monolayer graphene is placed on the silver substrate surface with a periodic array of one-dimensional slits. Two absorption peaks are found to result from the hybridization of delocalized surface plasmon polaritons and localized magnetic plasmons. The positions of absorption peaks are accurately predicted by a coupling model of double oscillators. The full width at half maximum of absorption peaks is largely tuned from about 1–200 nm by changing the array period of slits. The effect of the slit size on absorption peaks is also investigated in detail. Our work is promising in applications for photoelectric devices.