光诱导光学晶格中高斯型孤子的开关行为

讨论了高斯型空间光孤子在光折变介质光学晶格的传输行为,运用分步傅里叶变换法对传输方程进行数值分析.研究表明:单个斜入射高斯型光孤子在周期性光学晶格中会局限于入射波导传输或在合适振幅的情况下穿过若干波导再自陷于某个波导;而当同时存在正入射和斜入射孤子时,两者相遇后会发生反射或透射,并可通过斜入射光孤子的振幅选择反射或透射.     

共振光子晶体中Laue孤子传播的动力学行为

从理论上研究了Laue孤子传播的动力学行为，并通过数值模拟验证了这些行为.结果表明，由于非线性衍射，入射脉冲会分裂产生四种模式，其中产生的Laue孤子的传播行为与一般共振介质中孤子的传播行为相似.     

光折变晶体中屏蔽空间亮孤子及亮孤子对的演变

建立了光折变晶体在外加直流电场作用下的光传输理论模型,运用分步傅里叶方法对传输方程进行了数值分析.结果表明:一阶亮孤子在光折变晶体中稳定传播,二阶亮孤子发生周期性的振幅变化;一阶亮孤子对在光折变晶体中发生周期性耦合作用,耦合周期与孤子对输入脉冲的中心距离有关,距离越大,耦合周期越长;二阶亮孤子对同样发生耦合,耦合周期也取决于输入脉冲的中心距离,同时每一个二阶亮孤子会发生分裂,分裂成一大一小两个孤子;此外,在同样的中心距离下,二阶亮孤子对的耦合周期比一阶亮孤子对短.     

Entanglement dynamics of two qubits coupled by Heisenberg XY interaction under a nonuniform magnetic field in a spin bath

This paper investigates the entanglement dynamics of a Heisenberg XY model for a two-spin system in the presence of a nonuniform magnetic field.The master equations and the concurrence evolution equations for the initial α state are derived and analysed.It is shown that for the symmetric initial α state,only the nonuniform field can play a role in entanglement dynamics while the uniform field and the bath will not play such a role.For the asymmetric α state,the nonuniform field leads to the beat pattern oscillation of the concurrence evolution.The inhomogeneity of the field can enhance the entanglement by suppressing the decoherence effects of both the spin-orbit interaction and the spin bath.     

原子类原子系统光学特性的量子相干调控应用基础研究

简要介绍了在原子类原子小量子系统光学特性的量子相干调控应用基础研究方面所取得的一些成果,主要包括周期调制场控制弱光孤子传输、光学腔超窄线宽输出、非对称双量子阱中光学前驱波的分离以及极性分子系统中的电磁诱导透明现象等.     

Anti-Stokes Frequency Shift and Evolution in Polarization-Maintaining Photonic Crystal Fiber with Two-Zero Dispersion Wavelengths

Using the tunable pump pulses with about lOO fs pulse duration and 1064 nm central wavelength; the polarization-, wavelength- and power-dependent anti-Stokes lines are generated and modulated simultaneously in a polarization-maintaining photonie crystal fiber （PM-PCF） with two zero-dispersion wavelengths. By accurately controlling the polarization directions, the wavelength and the power of the pump pulse in the fiber anomalous region close to the second zero-dispersion wavelength of the PM-PCF, the output anti-Stokes pulse spectra can be tuned between 563 nm and 603 nm, which is in good agreement with the theoretical simulation. The color conversion of the mode image from yellow to orange is also observed with the different polarization pump pulses. These results can be attributed to the combined interaction between the fiber birefringence （including linear- and nonlinear- birefringence） and dispersion, and are attributed to phase-matching parametric four-wave mixing.     

叉形光栅法产生分数阶涡旋光的实验探究

衍射和光栅是基础光学课程和光学实验的重要内容，在传统光学技术和前沿科学研究中有重要的作用和应用。文章以分数阶涡旋光为研究对象，利用空间光调制器设计了基于叉形光栅的衍射效应产生分数阶涡旋光的实验，编写了分数阶叉形光栅的计算机程序，实验上产生和观测了分数阶涡旋光，分析了分数阶涡旋光的特点和强度分布。通过本实验，学生进一步加深了对衍射和光栅特性的理解，激发了对光学前沿研究和探索的兴趣，拓展了学生的专业知识，提升了对光学研究和光场调控的创新意识。     

有源和无源的无磁非互易研究进展

根据洛伦兹互易定理,在通常的光学系统中,交换信号源和探测器的位置后接收到的光信号不变。这为光路设计和分析带来了方便。在全光通信和量子网络中,需要有效地控制光信号的定向传输以避免反射光对信号的干扰、分离相向传输的光信号等,因此需要只允许光单向传输的非互易器件。以磁光隔离器为背景切入,简单介绍磁光领域的研究现状。重点从有源和无源两个方面对无磁非互易领域的发展进行综述,以展现量子光学在无磁非互易领域的重要应用。     

Nonreciprocal transmission of multi-band optical signals in thermal atomic systems

Multi-band signal propagation and processing play an important role in quantum communications and quantum computing.In recent years,optical nonreciprocal devices such as an optical isolator and circulator are proposed via various configurations of atoms,metamaterials,nonlinear waveguides,etc.In this work,we investigate all-optical controlled nonreciprocity of multi-band optical signals in thermal atomic systems.Via introducing multiple strong coupling fields,nonreciprocal propagation of the prob...     

High-order harmonic generation in sub-one-cycle regime

We theoretically investigate the high-order harmonic generation from the hydrogen atom driven by the laser pulses with the durations less than the optical cycle.It is found that the switching term of the laser field may have an obvious influence on the cutoff,intensity or plateau structure of the high-order harmonic spectrum.Generally speaking,the switching term can shorten the cutoff of the high-order harmonic spectrum for a relatively longer pulse and extend the cutoff for a relatively shorter pulse.