Design of tunable selective light-absorbing metasurfaces driven by intrinsically chiral quasi-bound states in the continuum.

Chiral metasurfaces with high quality factors (Q-factors) and strong circular dichroism (CD) are excellent platforms for studying chiral optical response. Here, a design is proposed of an intrinsic chiral silicon metasurface driven by bound states in the continuum (BIC), with ultra-high Q-factor (Q = 3722) and chirality response close to the unit CD (CD > 0.99).

Design of a vortex metalens with high focusing efficiency using propagation phase.

Three vortex-focused beams are produced with linearly polarized light along the or axis at a wavelength of 1550 nm. First, a polarization-independent vortex metalens with a topological charge of three and focal length of 3000 nm is designed by selecting cylindrical-shaped elements. This design has a focusing efficiency of 83%.

Multifunctional tunable visible light metalens based on double-layer barium titanate.

A tunable metalens plays an indispensable role in the development of integrated optics, multi-imaging systems, etc. We propose a multifunctional tunable metalens that combines a double-layer barium titanate (BTO) structure and geometric phase in the visible light band. The refractive indices of the upper and lower layer BTO nanorods can be tuned continuously and independently by applying external voltage (0-60 V), and the lower layer can be converted between a full-wave plate and normal scattering unit, while the scatterers of the upper layer can be switched between a half-wave plate and full-wave plate.

Three-dimensional AgS cubes for switchable multi-wavelength ultrashort pulse application.

Three-dimensional (3D) materials are widely used in optoelectronics, thermodynamics and ultrafast fiber lasers because of their excellent nonlinear optical properties. Silver sulfide (AgS) is a kind of 3D material with a unique cubic structure and large absorption coefficient. In this paper, a double-balance detection system is used to measure the saturation absorption intensity of AgS as 226.

SnSe realizes soliton rain and harmonic soliton molecules in erbium-doped fiber lasers.

Two-dimensional layered metal chalcogenides (LMCs) are widely used in battery anode materials, energy conversion, and semiconductor devices, because of their high energy storage characteristics, high thermoelectric characteristics, and large electron mobility. SnSe as a kind of LMC has strong nonlinear optical characteristics. However, its research on dissipative system dynamics as a saturable absorber has not been studied.

Electrochemical Peeling Few-Layer SnSe for High-Performance Ultrafast Photonics.

In recent years, the photoelectric properties and nonlinear optical properties of layered metal chalcogenides (LMCs) have attracted extensive attentions. Because of lower phonon thermal conductivity, larger energy storage rate, and larger electron mobility, LMCs are widely studied in the fields of thermoelectric energy conversion, battery electrode materials, and semiconductor devices. As 2D LMCs, SnSe nanosheets (Ns) are connected to each other by van der Waals force, which makes it possible to use electrochemical methods to help peel off the thin layer structure.