Photorefractive two-wave mixing phase coupling measurement in a self-stabilized recording regime

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

The measurement of the phase coupling. between the two-wave mixed transmitted and diffracted beams behind a photorefractive material is directly obtained using a self-stabilized recording technique. These phase coupling data are used to compute the Debye screening length on an undoped Bi(12)TiO(20) crystal. The diffraction efficiency, which is obtained in two different ways from the same self-stabilized experimental run, is similarly processed to compute the Debye length too. The Debye length is also measured for Pb- and Zr-doped Bi(12)TiO(20) crystals, and from this parameter the corresponding effective density of traps is computed and shown to be lower than for the undoped sample.