Yanqing Shen

Electric control of enhanced lateral shift owing to surface plasmon resonance in Kretschmann configuration with an electro-optic crystal

In this paper, the electric control of enhanced lateral shift owing to surface plasmon excitation in the Kretschmann configuration with an electro-optic crystal prism is analyzed. The large positive and negative lateral shifts are due to the excitation of surface plasmon resonance. The sign and the magnitude of the lateral shift can be conveniently controlled by adjusting the applied electric field as well as by altering the angle of incidence. Angular modulation in this configuration can be replaced by the modulation of the applied electric field since their effects on reflectivity, phase and lateral shift of the reflected beam are similar. Numerical simulations confirm the theoretical analysis.

Field-induced enhancement of voltage-controlled diffractive properties in paraelectric iron and manganese co-doped potassium–tantalate–niobate crystal

High voltage-controlled diffraction efficiency of 78.3% was obtained in paraelectric potassium–tantalate–niobate crystal co-doped with iron and manganese. It was found that the recording time required to achieve maximum diffraction efficiency can be significantly reduced through the application of an external electric field on the crystal during writing. More importantly, the maximum diffraction efficiency maintained a considerably high value under a low external field at different writing angles. The external-field-enhanced space-charge fields were also calculated to interpret the important role of the enhancement effect. The results show that employing an enhanced electric field is of great significance for electroholography device applications.

Two-dimensional electron gas in the KNbO3:Y ultrathin film

First-principles calculations are used to study KNbO3:Y ultrathin film. The conducting two-dimensional electron gas (2DEG) is found in KNbO3:Y film, whereas SrTiO3:Y superlattice is insulating [Science 331, 886 (2011)]. The carrier density of 2DEG of KNbO3:Y film is twice that of LaTiO3/SrTiO3 superlattice, which is in agreement with the theoretical results of KNbO3:La superlattice. It is found that the charge densities of different monolayers are modulated by the polarization effect of KNbO3. We predict that 2DEG may be in other rare-earth atoms-doped KNbO3 film.