Discrete structure of ultrathin dielectric films and their surface optical properties

利用超薄跨维度等离激元薄膜控制单光子发射

Controlling Single-Photon Emission with Ultrathin Transdimensional Plasmonic Films

本研究通过理论分析超薄跨维度等离激元薄膜对二能级量子偶极子发射体的影响，发现减小薄膜厚度可显著增强光子反聚束效应，为固态单光子源器件工程及集成量子光子学平台发展提供指导。

Second Harmonic Generation from Phononic Epsilon-Near-Zero Berreman Modes in Ultrathin Polar Crystal Films

Immense optical field enhancement was predicted to occur for the Berreman mode in ultrathin films at frequencies in the vicinity of epsilon near zero (ENZ). Here, we report the first experimental proof of this prediction in the mid-infrared by probing the resonantly enhanced second harmonic generation (SHG) at the longitudinal optic phonon frequency from a deeply subwavelength-thin aluminum nitride (AlN) film. Employing a transfer matrix formalism, we show that the field enhancement is completely localized inside the AlN layer, revealing that the observed SHG signal of the Berreman mode is sol…

含硅层多层堆叠中超薄 a-Ge 薄膜的飞秒激光晶化

Femtosecond Laser Crystallization of Ultrathin a-Ge Films in Multilayer Stacks with Silicon Layers

本文用 1500 nm、70 fs 激光研究含硅多层堆叠中 3.5 nm a-Ge 薄膜的选择性晶化，发现其抑制应力诱导爆发式晶化而经由热熔化进行。

Implementing strong interference in ultrathin film top absorbers for tandem solar cells

Strong interference in ultrathin film semiconductor absorbers on metallic back reflectors has been shown to enhance the light harvesting efficiency of solar cell materials. However, metallic back reflectors are not suitable for tandem cell configurations because photons cannot be transmitted through the device. Here, we introduce a method to implement strong interference in ultrathin film top absorbers in a tandem cell configuration through use of distributed Bragg reflectors (DBRs). We showcase this by designing and fabricating a photoelectrochemical-photovoltaic (PEC-PV) stacked tandem cell …

Spatiotemporally Separable Biphoton State Generated by Spontaneous Four Wave Mixing in Ultrathin Nonlinear Films

We theoretically investigated the biphoton state generated by spontaneous four wave mixing (SpFWM) in ultrathin nonlinear films. The expression of the biphoton state is obtained by perturbation method, in which the longitudinal phase mismatch term is eliminated due to the ultra-small nonlinear interactive length. As a result of the relaxation of the longitudinal phase match condition, frequency bandwidth of the biphoton state could be very large. The correlation function of the biphoton state is analyzed, showing that the space and time in the biphoton correlation of this state are factorable.…

Broadband perfect absorption of ultrathin conductive films with coherent illumination:Superabsorption of microwave radiation

Absorption of microwave by metallic conductors is exclusively inefficient, though being natively broadband, due to the huge impedance mismatch between metal and free space. Reducing the thickness to ultrathin conductive film may improve the absorbing efficiency, but is still bounded by a maximal 50% limit induced by the field continuity. Here, we show that broadband perfect (100%) absorption of microwave can be realized on a single layer of ultrathin conductive film when it is illuminated coherently by two oppositely incident beams. Such an effect of breaking the 50% limit maintains the intrin…

Giant Terahertz Polarization Rotation in Ultrathin Films of Aligned Carbon Nanotubes

For facile manipulation of polarization states of light for applications in communications, imaging, and information processing, an efficient mechanism is desired for rotating light polarization with a minimum interaction length. Here, we report giant polarization rotations for terahertz (THz) electromagnetic waves in ultrathin (~45 nm), high-density films of aligned carbon nanotubes. We observed polarization rotations of up to ~20° and ~110° for transmitted and reflected THz pulses, respectively. The amount of polarization rotation was a sensitive function of the angle between the incident TH…

Epsilon-Near-Zero (ENZ) 模式对超薄膜间 Casimir 相互作用的影响

The Effect of Epsilon-Near-Zero (ENZ) Modes on the Casimir Interaction between Ultrathin Films

首次从实频率力分布角度研究超薄膜间 Casimir 相互作用，发现 ENZ 模式产生显著排斥贡献且与间距无关，揭示了其在纳米机械系统中的工程化潜力。

Near-infrared single-photons from aligned molecules in ultrathin crystalline films at room temperature

We investigate the optical properties of Dibenzoterrylene (DBT) molecules in a spin-coated crystalline film of anthracence. By performing single molecule studies, we show that the dipole moments of the DBT molecules are oriented parallel to the plane of the film. Despite a film thickness of only 20 nm, we observe an exceptional photostability at room temperature and photon count rates around one million per second from a single molecule. These properties together with an emission wavelength around 800 nm make this system attractive for applications in nanophotonics and quantum optics.

Ultrathin and ultrasmooth gold films on monolayer MoS2

Sub-10 nm continuous metal films are promising candidates for flexible and transparent nanophotonics and optoelectronics applications. In this Letter, we demonstrate that monolayer MoS2 is a perspective adhesion layer for the deposition of continuous conductive gold films with a thickness of only 3-4 nm. Optical properties of continuous ultrathin gold films deposited on two-dimensional MoS2 grown by chemical vapor deposition are investigated by spectroscopic ellipsometry over a wide wavelength range (300-3300 nm). Results show that optical losses in ultrathin films increase with decreasing thi…

探索三元过渡金属二硫属化物介电函数的温度依赖性：迈向热驱动超薄光子组件

Probing the temperature dependence of dielectric function of ternary transition metal dichalcogenides: towards thermo-driven ultrathin photonic components

研究探索三元过渡金属二硫属化物介电函数温度依赖性，通过对MoSSe和WSSe在特定光谱区域与温度窗口研究，揭示介电响应规律，利用其光学色散设计近红外光子透镜，为热驱动光电器件创建提供关键见解。