The Study On Quantum Coherent Effect And Electromagnetically Induced Self-imaging In The Doped Rare-earth Crystal

The study of quantum coherence effects between laser and matter is one of the hot topics in optics,and the related topics are also interesting,such as electromagnetically induced transparency?EIT?,lasing without inversion?LWI?,the refractive index enhanced and so on.The research on EIT is always developed in gas media for its simple structure,long decoherence time and more rapidly and successfully realized in the experiment.However,for the manipulation and preparation,there are some restrictions in the practical applications.Compared with gas media,recently the crystals doped with earth attract much attention because they have the advantages of compact-sized,no diffusion of interface,and are easily integrated in communication networks,and will be important in all optical networks and quantum computers.In this Letter,according to density matrix method,we study the absorption and dispersion properties of the probe light in theEu^3?10?:Y₂ SiO₅ and thePr^3?10?:Y₂ SiO₅ crystal and presents to the influences of the parameters on the transmission and the refractive index.Coupling by the controlling field,the system is induced to the gradient index structure.The electromagnetically induced self-imaging can be realized in solid media and the relationships among the Rabi frequency of the controlling field,the dope-ion concentration and the first positions of self-imaging are presented.The interesting results are meaningful and may have potential application in the imaging storage and processing.This dissertation has five chapters.Chapter One introduces some important quantum coherence theory,including coherent population trapping?CPT?,EIT and LWI.Chapter Two recommend theoretical model of the three-level?43?-type atom system,and obtain the expression for the susceptibility of the doped rare-earth crystal.In the third chapter,we analyze the transverse optical properties of the three level?43?-type Eu^3?10?:Y₂ SiO₅ atom system.We investigate the influences of probe detuning,the Rabi frequency of the control field and the laser line width,the influences of the dope-ion concentration on the transverse optical properties are also discussed.The study of the self-imaging in theEu^3?10?:Y₂ SiO₅ and thePr^3?10?:Y₂ SiO₅crystal is in the forth chapter.When the control field is a Gaussian beam,we plot the relationships among the Rabi frequency of the controlling field,the dope-ion concentration and the first positions of self-imaging.We also present influences of each parameter on the first positions of the self-imaging.The last chapter is the summary.