Characterization of a photorefractive rhodium doped barium titanate at 1.06 μm

Two-wave mixing in photorefractive BaTiO_3:Rh at 106 µm in the nanosecond regime

“…We attribute most of the extra reduction of G to experimental problems: the control of the overlap of the beams inside the crystal imposed a large-diameter pump beam (2.5 mm), which favors the oscillation of spurious beams as observed in the cw regime. 1 To summarize, we have demonstrated high (G 14.2 cm 21 ) two-wave mixing gain at 1.06 mm in the nanosecond regime in photorefractive BaTiO 3 :Rh. We observed that the required averaged density of energy was roughly the same as in the cw regime.…”

“…The attenuation configuration diminishes the oscillation of spurious beams in the crystal, which has been shown, in the cw regime, to compete with the desired photorefractive grating. 1 The experiments were conducted with extraordinary polarizations for energies ranging from 10 to 200 mJ͞pulse incident upon the sample, corresponding to average illuminations per pulse of 1-20 MW cm 22 . The experimental data for G versus illuminations are plotted in Fig.…”

Quantitative determination of charge transfer parameters of photorefractive BaTiO3:Rh from EPR-based defect studies

“…From that, we can derive the value of N e f f being (0.9 ± 0.2) × 10 17 cm −3 . This 'experimental' value of N e f f will now be compared to the one deduced from the data in table 1, as based on a compact expression for N e f f , derived, e.g., by Huot et al [8] for the three-valence model:…”

“…In the appendix we give the detailed expression for η(I ) as specified for the three-valence model by Huot et al [8]. It is seen there that η(I ) does not depend on k g .…”

“…The electrooptic tensor of the host lattice contains rather large coefficients, and thus even relatively few transposed charges are sufficient to create measurable index changes. Moreover, doping with Rh is known to improve the infrared sensitivity of the material [5][6][7][8][9]. Figure 1 shows the three elementary schemes describing light-induced charge transfer in crystals [10].…”