Mn:Fe:LiNbO3 crystals were grown using the conventional Czochalski method. The phase conjugate reflectivity and response time were measured by four-wave fixing method with Ar+ laser (488nm) as light source. Non-degenerate phase conjugate wave varying frequency was obtained in Mn:Fe:LiNbO3 and Fe:LiNbO3 crystals with Ar+ laser (488nm) and He-Ne laser (632.8 nm) as light source. The maximum of phase conjugate reflectivity varying frequency of Mn:Fe:LiNbO3 crystal was up to 920%, three orders of magnitude than that of Fe:LiNbO3 crystal. Based on Li vacancy model, we discussed the photorefractive improving mechanism of Mn:Fe:LiNbO3 crystal.
CuO and Co2O3 were doped in KNSBN and Czochralski method was used to grow Cu:Co:KNSBN crystal for the first time. ZnO and Fe2O3 were doped in LiNbO3 and Czochralski method was used to grow Zn:Fe:LiNbO3 crystals. The diffraction efficiency and response time of the Zn:Fe:LiNbO3 crystals were measured. The response speed of the Zn:Fe:LiNbO3 crystal is four times higher than that of the Fe:LiNbO3 crystal. The self-pumping phase conjugate reflectivity and respond time of the Cu:Co:KNSBN crystal were measured. The result shows that the self-pumping phase conjugate reflectivity of the Cu:Co:KNSBN crystal is two time higher than that of KNSBN crystal. Zn:Fe:LiNbO3 and Cu:Co:KNSBN were used as storage element and self-pumping phase conjugate mirror, respectively, to make the holographic associative storage experiment. The excellent results were gained.
Ce:Cu:BSO crystal co-doped with CeO2 and CuO has been grown by the Czochralski method. The lattice constants, absorption spectrum, exponential gain coefficient, diffraction efficiency and respond time are measured. The lattice constants of Ce:Cu:BSO crystal are always larger than that of BSO crystal. Due to Ce and Cu ionic radii are larger than that of Bi3+ and Si4+, the lattice constants of doped crystal are larger than that of BSO crystal, thus make the absorption edge shift to the longer wavelength spectral range. The results indicate that the photorefraction of Ce:Cu:BSO crystal improves and the exponential gain coefficient and diffraction efficiency of Ce:Cu:BSO crystal improves two times compared with that of undoped BSO crystal. Furthermore, the photorefractive effect and the holographic storage effect of Ce:Cu:BSO crystal is better than that of undoped BSO crystal.
In this paper, the 3-D measuring system based on structure-light, which principle is that its distortion can be transformed into the height change in the direction of the stripe if a single-stripe light is emitted and observed sideways and a generator emitting a single-stripe light and a camera can make up of a 3-D measuring system, was designed in order to inspect the shape of product surface on-line in the industrial production. At first, this paper introduces the structure of the 3-D measuring system using the single-stripe structured-light and its buildup. At second, its operating principle is introduces, its mathematical model is established and the calibrating method for it is put forward. At last, its prototype is produced and calibrated. The experimental result shows that the mathematical model put forward in this paper is suitable for engineering, the system calibration method suggested in this paper becomes more simple than other calibration methods, the system prototype has the range of 630mm(Depth)×400mm(Height) and the accurate of 0.3%(Depth)×0.5%(Height).
In this paper, a 3-D noncontact measuring method using single-line structural light is put forward. First, the light path for measuring is designed according to the principles, then the mathematical model is derived, in which necessary parameters are defined. Finally the implementation of the system is given out, and the experimental testing results as well.