Dressed Four-Wave Mixing Spectroscopy Modified by Polarization Interference and Atom-Wall Collision in Micrometric Thin Cells

Dressed four-wave mixing （DFWM） spectroscopy is investigated theoretically in some micrometric thin cells. It is found that DFWM spectra can be modified by polarization interference of atoms and transient effects induced by atom-wall collision. This modification can lead to width-narrowing of DFWM lines and facilitates to implement experiment of high resolution DFWM spectroscopy in a confined atomic system.     

Spatial Dispersion Induced by Cross-Phase Modulation

We demonstrate our experiment of controlling spatial displacements of the probe beam induced by the cross-Kerr effect in a three-level V-type atomic system. By increasing the atomic density or the intensity of strong control laser beams, spatial displacements are enhanced. We further study the difference of effects from the atomic density and the laser intensity. In addition, the spatial displacement efficiencies of the probe beam in different energy level atomic systems are compared. Such studies of controlling spatial displacements can have potential applications in soliton deflection, spatial optical switch and generating spatially correlated （entangled） laser beams in multi-level EIT systems.     

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.     

Phase dispersion of Raman and Rayleigh-enhanced four-wave mixings in femtosecond polarization beats

Based on color-locking noisy field correlation in three Markovian stochastic models, phase dispersions of the Raman- and Rayleigh-enhanced four-wave mixing (FWM) have been investigated. The phase dispersions are modified by both linewidth and time delay for negative time delay, but only by linewidth for positive time delay. Moreover, the results under narrowband condition are close to the nonmodified nonlinear dispersion and absorption of the material. Homodyne and heterodyne detections of the Raman, the Rayleigh and the mixing femtosecond difference-frequency polarization beats have also been investigated, separately.     

Coexisting Raman- and Rayleigh-Enhanced Four-Wave Mixing in Femtosecond Polarization Beats

Based on the polarization interference of Raman- and Rayleigh-enhanced four-wave mixing processes, heterodyne detection of the Raman, Rayleigh and coexisting Raman and Rayleigh femtosecond difference-frequency polarization beats is investigated in the cw and the three Markovian stochastic models, respectively. These two processes exhibit asymmetric and symmetric spectra, respectively, and the thermal effect in them can be suppressed by field-correlation method. Such studies of coexisting Raman- and Rayleigh-enhanced four-wave mixing processes can have important applications in coherence quantum control, and quantum information processing.     

Interaction of Triply-Dressing Electromagnetically Induced Transparency in Five-level Folding Atomic System

We consider a five-level atomic folding system, which involve two kinds of dressing mechanisms （the nested- cascade and the sequential-cascade） in interaction of three-dressing fields, the numerical results show that three- dressing fields are interchangeable under certain conditions, which can be considered as two four-level sub-system configurations （a nested-cascade N configuration and a sequential-cascade inverted-Y configuration）.     

Observation of the near transform-limited high-resolution tunable far-ultraviolet light

This paper studies the near transform-limited high-resolution tunable far-ultraviolet light which is generated by narrow-band tunable light both theoretically and experimentally. It presents the theoretical work on conversion efficiency of sum-frequency, which is restricted by phase-matching angle, walk-off angle and phase distortion and so on, and conducts an experiment to check this work successfully. Also the origin of chirp of a dye laser is analysed.