Second-order temporal interference of two independent light beams at an asymmetrical beam splitter

The second-order temporal interference of classical and nonclassical light at an asymmetrical beam splitter is discussed based on two-photon interference in Feynman＇s path integral theory. The visibility of the second-order interference pattern is determined by the properties of the superposed light beams, the ratio between the intensities of these two light beams, and the reflectivity of the asymmetrical beam splitter. Some requirements about the asymmetrical beam splitter have to be satisfied in order to ensure that the visibility of the second-order interference pattern of nonclassical light beams exceeds the classical limit. The visibility of the second-order interference pattern of photons emitted by two independent single-photon sources is independent of the ratio between the intensities. These conclusions are important for the researches and applications in quantum optics and quantum information when an asymmetrical beam splitter is employed.

Effects of Ti content on dielectric and energy storage properties of(Pb_(0.94)La_(0.04))[(Zr_(0.70)Sn_(0.30))_(1-x)Ti_(x)]O_(3)ferroelectric/antiferroelectric ceramics

Ferroelectric/antiferroelectric(FE/AFE)ceramics with composition of(Pb_(0.94)La_(0.04))[(Zr_(0.70)Sn_(0.30))_(1-x)Ti_(x)]O_(3)were fabricated via solid state reaction and the effects of Ti content on dielectric and energy storage properties were studied.High releasable energy density of 1.03 J/cm^(3)was obtained when x=0:12 under 65.7 kV/cm.With increasing Ti content,both the forward and backward phase transition fields would decrease.When x=0.16,the dielectrics would be under FE state at room temperature(22℃)and the phase transition from FE to AFE and then to paraelectric(PE)was observed with temperature rise.The discharge properties were also studied and the results proved that the stored charge in AFE could be released much more completely than that in FE.

SINTERING BEHAVIOR AND MICROWAVE DIELECTRIC PROPERTIES OF NOVEL LOW TEMPERATURE FIRING Bi_(3)FeMo_(2)O_(12)CERAMIC

In the present work,a novel low temperature-ring Bi_(3)FeMo_(2)O_(12) ceramic was synthesized via the solid-state reaction method.The monoclinic Bi_(3)FeMo_(2)O_(12) phase can be formed at a low temperature 670℃.A relative density above 96%can be obtained when sintering temperature is above 800℃.The Bi_(3)FeMo_(2)O_(12) ceramic sintered at 845℃ for 2 h shows high microwave dielectric performance with a permittivity-27.2,a Qf value of 14,500GHz and a temperature coefficient of-80 ppm/℃.It might be a candidate for low temperature co-fired ceramics technology.

DC BIAS ELECTRIC FIELD DEPENDENT PIEZOELECTRICITY FOR[001]POLED Pb(In_(1/2)Nb_(1/2))O_(3)-Pb(Mg_(1/3)Nb_(2/3))O_(3)-PbTiO_(3) CRYSTALS

The longitudinal piezoelectric response of[001]poled rhombohedral and orthorhombic Pb(In_(1/2)Nb_(1/2))O_(3)-Pb(Mg_(1/3)Nb_(2/3))O_(3)-PbTiO_(3)crystals were investigated with respect to DC bias electric field,being in the range of-2-15 kV/cm.For rhombohedral crystals with compo-sitions far away from morphotropic phase boundary(MPB),the piezoelectric response generally decreased with increasing positive DC bias field,while for crystals with MPB compositions,the piezoelectric response firstly decreased and then increased as function of DC bias.The piezo-electric response was found to decrease drastically when DC bias larger than phase transition feld.On the other hand,the piezoelectric response was slightly enhanced for all the crystals as function of negative DC bias prior to the depolarization.To explain the obtained results,the field dependent piezoelectric cofficients in domain engineered crystals were analyzed based on ther-modynamic approach.