The space-charge-field harmonics in the refractive-index grating generated in a bismuth silicate crystal to which a square-wave external electric field is applied were examined theoretically and experimentally at high interference-pattern contrasts. The model taking into account three spatial harmonics ensures good agreement with experimental data for the fundamental- and second-harmonic gratings. By fitting the experi- mental data with theoretical curves, the acceptor concentration and the product of the carrier mobility and recombination time in the crystal were evaluated.
展开▼
