Photorefractive effects and light‐induced charge migration in barium titanate

We propose a new theoretical model for the light‐induced migration of charges which mediates the ’’photorefractive effect’’ (light‐induced refractive index change) in barium titanate and other crystals. We also present experimental results of various effects of this light‐induced charge migration in a single‐domain crystal of barium titanate, specifically, (1) energy transfer between two intersecting optical beams, (2) optical four‐wave mixing and optical‐beam phase conjugation, (3) erasure of spatial patterns of photorefractive index variations, and (4) photoconductivity. The theoretical model predicts the observed dependences of these effects on (1) beam intensities, directions, and polarizations, (2) crystal orientation, and (3) on an externally applied dc electric field. Time dependences of transients as well as steady‐state magnitudes are predicted. In this model, identical charges migrate by hopping between adjacent sites, with a hopping rate proportional to the total light intensity at the starting...

[1]  Frank K. Tittel,et al.  Nonlinear dynamic theory for photorefractive phase hologram formation , 1976 .

[2]  M. DiDomenico,et al.  Dielectric and optical properties of melt-grown BaTiO3 , 1968 .

[3]  D. B. Fraser,et al.  HOLOGRAPHIC STORAGE IN LITHIUM NIOBATE , 1968 .

[4]  Amnon Yariv,et al.  Four wave nonlinear optical mixing as real time holography , 1978 .

[5]  J. J. Amodei,et al.  Coupled‐Wave Analysis of Holographic Storage in LiNbO3 , 1972 .

[6]  J. Amodei.  Electron Diffusion Effects during Hologram Recording in Crystals , 1971 .

[7]  W. D. Johnston.  Optical Index Damage in LiNbO3 and Other Pyroelectric Insulators , 1970 .

[8]  A. D. Aronoff,et al.  Electric Field Distriutions in Dielectrics, with Special Emphasis on Near-Surface Regions in Ferroelectrics , 1971 .

[9]  G. D. Boyd,et al.  OPTICALLY‐INDUCED REFRACTIVE INDEX INHOMOGENEITIES IN LiNbO3 AND LiTaO3 , 1966 .

[10]  D. W. Vahey,et al.  A nonlinear coupled‐wave theory of holographic storage in ferroelectric materials , 1975 .

[11]  W. D. Cornish,et al.  Theory of formation of phase holograms in lithium niobate , 1974 .

[12]  G. D. Boyd,et al.  LiNbO3: AN EFFICIENT PHASE MATCHABLE NONLINEAR OPTICAL MATERIAL , 1964 .

[13]  J. Lamacchia,et al.  Optically Induced Refractive Index Changes in BaTiO3 , 1970 .

[14]  F. Micheron,et al.  Volume hologram recording and charge transfer process in Bi12SiO20 and Bi12GeO20 , 1977 .

[15]  Robert W. Hellwarth,et al.  Generation of time-reversed wave fronts by nonlinear refraction* , 1977 .

[16]  H. Kogelnik.  Coupled wave theory for thick hologram gratings , 1969 .

[17]  F. S. Chen,et al.  Optically Induced Change of Refractive Indices in LiNbO3 and LiTaO3 , 1969 .