HOLOGRAPHIC-CURRENT STUDY IN LASER AND PHOTOREFRACTIVE CRYSTALS

We modified the theory of the holographic current, describing both the steady-state and the transient contributions and accounting for the p arameters of the measurement circuit. In the model of the transient ph otocurrent we connected the observables of the steplike modulation exp eriment with the carrier transport parameters such as carrier diffusio n and screening length, carrier effective lifetime, and Maxwell relaxa tion time. Experimentally, we have shown that theoretically predicted dependences of the photocurrent amplitude and relaxation time on the g rating period, the light intensity, and the depth of the modulation we re observed not only in the photorefractive Sr1-xBaxNb2O6 and Bi12TiO2 0, crystals but in Er-doped YSGG laser crystals as well. (C) 1996 Opti cal Society of America.