用于下一代传感和光源的新型材料、光纤及器件

制造技术与复杂模型、设计工具的进步使微纳结构光学器件的实现成为可能。微纳结构光学器件可用于导光与光的相互作用,液态或气态新型光源和传感器件。IPAS致力于新型光学材料研究与开发,将玻璃工艺和光纤开发有机结合,重点研究微纳结构光纤,光纤表面功能处理和器件开发。介绍了IPAS的研究实力和近年的发展概况,其中包括中红外光学材料、纳米粒子嵌入玻璃材料、新型化学和生物传感器(适用于超低量样本及/或体内样本)、激光器件,以及用于光数据处理的新型高非线性光纤。     

Multisymplectic implicit and explicit methods for Klein–Gordon–Schrödinger equations

We propose multisymplectic implicit and explicit Fourier pseudospectral methods for the Klein-Gordon-Schrödinger equations. We prove that the implicit method satisfies the charge conservation law exactly. Both methods provide accurate solutions in long-time computations and simulate the soliton collision well. Numerical results show the abilities of the two methods in preserving charge, energy, and momentum conservation laws.     

氧化石墨烯/壳聚糖复合薄膜材料的制备及其非线性光限幅效应的研究

石墨烯及其衍生物作为新型碳纳米结构,由于其优异的光限幅性能而受到广泛关注,但现有的工作多侧重于其在液相体系中光限幅效应及其起因研究.本文以壳聚糖为成膜基质,将氧化石墨烯(GO)与壳聚糖(CS)在液相中均匀共混后成膜,对比研究GO溶液和GO-CS复合膜的光限幅效应及其起因.结果表明在线性透过率相同的情况下,GO在固相基质中表现出比液相基质更强的光限幅效应和更弱的非线性散射.这说明不同于碳纳米管简单的非线性散射,在GO中可能存在多种非线性光学效应.     

具时变刚度的相对转动非线性动力系统的周期解问题

建立了一类具有时变刚度,非线性阻尼力和强迫周期力项的相对转动非线性动力系统. 运用Mawhin重合度理论,得到了该模型的周期解存在唯一性结果,推广了已有的结果, 并且列举了具体的例子来说明本文的结果是新的. 关键词： 相对转动非线性动力系统 时变刚度 周期解 存在唯一性     

Tripartite Nonlinear Entangled State Representations in Quantum Mechanics

Based on the technique of integral within an ordered product of nonlinear bosonic operators we construct a kind of tripartite nonlinear entangled states, which can make up a complete set. As its application, we also derive nonlinear 3-mode charge-related entangled state. The essential point for constructing these states lies in choosing the appropriate charge operator.     

Nonlinear polarization rotation-induced pulse shaping in a stretched-pulse ytterbium-doped fiber laser

We report on controllable pulse shaping in a Yb-doped stretched-pulse fiber laser followed by a high-power chirped pulse amplifier. We demonstrate that the pulses after an extra-cavity grating pair change their intensity profile from Lorentz to Gaussian and then to sech2 shapes by adjusting the intra-cavity polarization through a quarter-wave plate inside the fiber laser cavity. The laser pulses with different pulse shapes exhibit pulse-to-pulse amplitude fluctuation of -- 1.02%, while the sech2-shaped pulse train is provided with a more stable free-running repetition rate as a result of the stronger self-phase modulation in the fiber laser cavity than Lorentz- and Gaussian-shaped pulse trains.     

Selective thermal emission from a patterned metalized plastic

A high-throughput hot-embossing and metal-deposition fabrication process based on compact-disc manufacturing has been employed to produce Coupled Resonant Cavity (CRC) structures for directionally and spectrally selective thermal emission at infrared wavelengths. The CRC structures were fabricated by hot embossing poly(methyl methacrylate) (PMMA) substrates, over which a layer of aluminum (Al) was deposited to support surface plasmons. The thermal emission behavior of the structures was predicted by Rigorous Coupled Wave Analysis (RCWA) of deposited metal profiles determined by the Blech model. It is shown that CRC structures which are initially under-imprinted may be brought to a resonant condition by increasing the metal deposition thickness, which is desirable for improving the thermal and mechanical properties of the structures. The primary source of deviation between the modeled and measured results was associated with surface curvature induced in the substrates during the fabrication process.     

Use of tunable second‐harmonic signal from KNbO3 nanoneedles to find optimal wavelength for deep‐tissue imaging

Nonlinear optical (NLO) responses of perovskite‐type nanostructures have a variety of potential applications owing to the highly efficient frequency conversion guaranteed by both the material itself and the nanometer‐scale configuration. KNbO₃ (KN) nanoneedles have been identified as a promising NLO material because of the superior broadband frequency conversion efficiency, and if incident light is propagating in a direction perpendicular to the axis of a nanoneedle, then the phase‐matching constraint can be relaxed. Here, the second‐harmonic generation (SHG) and third‐harmonic generation (THG) responses of both individual and clustered KN nanoneedles are reported. Based on these results, a novel method is proposed for determining the optimal excitation wavelength for NLO imaging of several biological samples, with KN nanoneedles acting as NLO agents. The method is shown to provide the optical features in the focal plane and a more reliable estimation of the optimal excitation wavelength for deep‐tissue imaging.     

Rogue Wave Solutions for Nonlinear Schrödinger Equation with Variable Coefficients in Nonlinear Optical Systems

In this paper, the generalized Darboux transformation is constructed to variable coefficient nonlinear Schrödinger (NLS) equation. The N-th order rogue wave solution of this variable coefficient NLS equation is obtained by determinant expression form. In particular, we present rogue waves from first to third-order through some figures and analyze their dynamics.