Abstract:The spectral hole-burning in SrFCl:Sm~(2+) at 77 K is studied. It has been obtained that the total area of holes in the inhomogeneous line shape is limited by the number of Sm~(3+) in the material and the maximum of total area (S_(hole)) of holes is proportional to the number of Sm~(3+). The integrated area (S_i) in the inhomogeneous line shape is proportional to the number of Sm~(2+) in the material. The value of'S_(hole)/S_i is equal to the ratio of the trivalent to the divalent samarium contents in the material.

Abstract:The nonlinear optical phase conjugation effect of F_3~+ centers in LiF crystals is observed using degenerate four-wave mixing technique. Using a pulsed dye laser as pump light, a maximum phase conjugate reflectivity of about 0.1% is obtained, The physical origin of the nonlinear saturation absorption and the four-wave mixing in F_3~+ center system is pointed out in theory according to the energy level propertry of the F_3~+ center in LiF crystals.

Abstract:The optical pulsation phenomenon which occurs in two-beam coupling and four-wave mixing in photorefractive LiNbO_3:Fe crystal is reported. This phenomenon is considered to originate from the trap-recharging wave in LiNbO_3:Fe crystal, which induces a moving phase grating in the photorefractive material.

Abstract:By excitation with CW laser the photoluminescence of the polyparaphenylene (PPP) has been measured. The crystallinity of the as-prepared polymer PPP is demonstrated by X-ray diffraction. The results indicate that the extrinsic luminescence is the broad red luminescence which peaks around 619.0nm and 728.1nm, whereas the Intrinsic luminescence has the sharp luminescence peaks which appear around 436.0nm and 466.0nm. The luminescence is mainly from non-crystalline region of PPP. The origin of the extrinsic luminescence is discussed.

Abstract:研究了a-SiN_x:H中带隙态和带尾态对光电导的影响。实验结果表明:退火引起光电导响应增加,光电流谱中的肩峰在200℃退火时消失,光生载流子的复合随退火温度的变化由双分子型变为单、双分子混合型,取决于光电导的带隙随退火温度的提高而略有增加。并从光电导测量定量地给出了悬键态密度。

Abstract:Cd_(1-x)Sm_xTe crystals (x=0.0005, 0.005, 0.01, 0.05) have been grown by Bridgman method for the first time. Photoluminescence measurements have been carried out in liquid nitrogen temperature range and the magnetization measurements have been made at 1.5K and magnetic fields up to 7T by using the extraction method. It is shown that the photoluminescence peak shifts toward the short wavelength (high energy) with the increase of x, corresponding to the decrease of lattice constant. The difference of paramagnetism between the rare-earth ions and transition metal ions is discussed and analyzed.

Abstract:The infrared study on oxygen-defect oomplexes in electron-irradiated and neutron-inradiated CZ-Si containing high carbon are reported. The annealing behavior of electron irradiation induced 830cm~(-1) band transforming to 889, 904, 969, 986 1000 and 1006cm~(-1) bands supports the multiple oxygen-defect complexes model previously proposed by Corbett and Stein. The broadening of neutron irradiation induced 830cm~(-1) band during annealing is due to the presence of satellite bands 842, 834, and 827cm~(-1) whese configuration is similar to that of 830cm~(-1) band. Three defect models are tentatively proposed to account for these satellite bands.

Abstract:The dependence of the intersubband transitions on pressure in strained In_(0.15) Ga_(0.85)As/GaAs multiple quantum wells has been studied in two samples with well widths of 8nm and 15nm, respectively, with photo- modulated transmission spectros copy by using a diamond anvil cell. The pressure coefficients of the energies for the intersubband transitions have been found to depend significantly on the well widths and be smaller than that of the band gap of constituents in bulk form. These results suggest that the critical thickness for strained In_(0.15)Ga_(0.85)As/GaAs layer should be smaller than 15nm.

Abstract:A simple HWE apparatus and the technology of using this appparatus to grown ZnSe single crystal epilayers on GaAs [100] plane are reported. The analysis of scanning electron microscope and X-ray diffraction shows that the epilayer of ZnSe single crystal is perfect.

Abstract:用红外反射光谱和X射线衍射方法研究了聚苯硫醚(PPS)在不同热处理条件下的结构和结晶度的变化,发现814cm~(-1)和804cm~(-1)峰分别对应PPS中晶态部分和非晶态部分的C-H面外弯曲振动,1067cm~(-1)～1088cm~(-1)双峰为构象敏感谱带,1067cm~(-1)峰对应无定形态链构象,而1088cm~(-1)峰对应PPS原粉的规整链构象。X射线衍射的结果进一步证实了这些结论。

Abstract:研制了高速、高效、低噪声的InGaAs/InGaAsP/InP长波长(1.0～1.7μm)台面型雪崩光电二极管(φ=75μm),器件采用分离的吸收区、雪崩区和能隙过渡区的SAGM结构。研究了器件最佳结构参数设置、在InP上匹配生长InGaAs、InGa AsP及其厚度和载流子浓度的控制问题。器件最大倍增因子大于50,灵敏度大于0.70μA/μW,暗电流I_D的典型值约为20nA(V_r=0.9V_B)。

Abstract:Using excitations by cathode-ray and ultraviolet radiation, the excitation and emission spectra of pure and doped ZnWO_4 with various dopants at room temperature are studied. The scintillation decay times are also measured for the above crystals using the single photon counting technique. It can be seen that there are four peaks in the excitation spectra, and the emission spectra contain three emission bands, known by spectra decomposition. The results show that the excitationand emission spectra of pure and doped ZnWO_4 are similar, Doping only changes the positions and relative intensities of the peaks. Analysis also shows that there are four decay times in pure and doped ZnWO_4 crystals. It seems thai the fast component may be increased by doping.