消多普勒三光子共振六波混频

研究多普勒系统中的位相共轭三光子共振六波混频(SWM).得到当入射激光为窄带线宽时，SWM频谱是消多普勒的，因此可成为一种研究原子或分子高激发态和高角动量态的高分辨相干非线性光谱学.本方法还具有位相匹配条件不严格，有良好的空间分辨率，光路配置简单等优点. 关键词： 六波混频 多普勒效应     

Opening four-wave mixing and six-wave mixing channels via dual electromagnetically induced transparency windows

Highly efficient four-wave mixing (FWM) and six-wave mixing (SWM) processes can coexist in a four-level Y-type atomic system due to atomic coherence. The simultaneously opened dual electromagnetically induced transparency windows in this four-level atomic system allow observation of these two nonlinear optical processes at the same time, which enables detailed studies of the interplay between the FWM and SWM processes. Three-photon and five-photon destructive interferences are also observed.     

倒V形四能级亚飞秒极化拍的三光子吸收和色散

基于孪生色锁噪声场的互相关效应，从理论上研究了倒V形(RV)四能级飞秒量级差频极化拍与极化拍中五阶非线性极化率，并提出了用一种相位敏感的方法来研究多能级原子相干造成的三光子六波混频过程.在抽泵光束为窄带末端情况下，场关联对信号和极化率的影响都很弱，在非窄带情况下，场关联会使极化强度自相干信号和极化拍信号产生关于零延时的不对称性和时域扫描上的辐射与物质失谐阻尼振荡(RDO)，而极化率会产生频域扫描上的RDO振荡.参考光信号是一路传播方向和六波混频信号稍有区别的双光于非简并四波混频信号.五阶非线性响应则由享生     

倒V形四能级亚飞秒极化拍的三光子吸收和色散

基于孪生色锁噪声场的互相关效应,从理论上研究了倒V形(RV)四能级飞秒量级差频极化拍与极化拍中五阶非线性极化率,并提出了用一种相位敏感的方法来研究多能级原子相干造成的三光子六波混频过程.在抽泵光束为窄带末端情况下,场关联对信号和极化率的影响都很弱,在非窄带情况下,场关联会使极化强度自相干信号和极化拍信号产生关于零延时的不对称性和时域扫描上的辐射与物质失谐阻尼振荡(RDO),而极化率会产生频域扫描上的RDO振荡.参考光信号是一路传播方向和六波混频信号稍有区别的双光于非简并四波混频信号.五阶非线性响应则由享生 关键词： 外差法 吸收 色散 非线性极化     

Spatial interference between four- and six-wave mixing signals

We experimentally demonstrate spatial interference between simultaneously generated four-wave mixing (FWM) and six-wave mixing (SWM) signals in a multilevel atomic system. By tuning the relative phase between the FWM and SWM processes the relative strengths between these two high-order nonlinear optical processes can be investigated.     

Multi-wave mixing Autler-Townes splitting in the five-level atomic system

We have demonstrated the Autler-Townes (AT) splitting of the four-wave mixing (FWM) process and the six-wave mixing (SWM) process in an electromagnetically induced transparency (EIT) window in five-level atomic vapor of 87 Rb. Moreover we discuss interactions of multi-dressed states. The experimental results agree well with the theoretical analysis.     

Four-wave mixing and six-wave mixing in a four-level confined atomic system

We have investigated coexisting four-wave mixing and six-wave mixing (SWM) in ultra-thin, micrometre and long vapour cells. There exists competition between Dicke-narrowing features and polarization interference in the micrometre cell. The oscillation behaviour of SWM signal intensities and linewidths results from destructive interference. With a larger destructive interference, the SWM signal in ultra-thin cells shows a narrow spectrum, in contrast to the long cell case. Due to the Dicke-narrowing features, a narrow spectrum can be obtained, and such spectra can be used for high precision measurements and metrological standards.     

Investigation of odd-order nonlinear susceptibilities in atomic vapors

We theoretically deduce the macroscopic symmetry constraints for arbitrary odd-order nonlinear susceptibilities in homogeneous media including atomic vapors for the first time. After theoretically calculating the expressions using a semiclassical method, we demonstrate that the expressions for third- and fifth-order nonlinear susceptibilities for undressed and dressed four- and six-wave mixing (FWM and SWM) in atomic vapors satisfy the macroscopic symmetry constraints. We experimentally demonstrate consistence between the macroscopic symmetry constraints and the semiclassical expressions for atomic vapors by observing polarization control of FWM and SWM processes. The experimental results are in reasonable agreement with our theoretical calculations.     

Observation of two multiwave mixing processes via dual optical pumping channels

Based on double optical pumping channels,we experimentally study the competition between two coexistent six-wave mixing(SWM) processes falling into two electromagnetically induced transparency windows by scanning the frequency of the probe field in two similar five-level atomic systems of 85Rb.By blocking one optical pumping channel unrelated to the four-wave mixing(FWM) process,one SWM process,together with the FWM process,generated by a conjugated small-angle static grating could be observed in the spectrum.Moreover,the other SWM process obtained by blocking the first SWM channel is also observed together with the FWM process in a lower N-type four-level subsystem.These experimental results agree well with theoretical predictions.     

Hybridization of spin-wave modes in a ferromagnetic microstrip

The dependence of the spectrum of spin-wave modes (SWMs) in a permalloy microstrip on the angle θ between the microstrip axis and the direction of the in-plane bias magnetic field has been studied with the use of ferromagnetic resonance at a frequency of 9.85 GHz. Hybridization between the quasi-homogeneous SWM and weakly localized SWM, which manifests itself as the repulsion of absorption lines of the microstrip spectrum, has been discovered at the angle θ ≈ 70°. The experimental results are in fair agreement with the numerically calculated SWM spectrum.