Hologram recording and erasure in GaAs:Cr with simultaneously applied electric and magnetic fields

摘要

Externally applied fields play crucial role in the enhancement of space charge electric field (E_(sc)) in photorefractive (PR) materials. Using band-charge transport model, E_(sc) (～10~5V/m) is obtained in presence of externally applied dc electric (E_0) and magnetic (B_0) fields simultaneously. Numerical estimation of GaAs:Cr shows that in presence of externally applied fields (optimum value of E_0 = 5 × 10~2 V/m and B_0 = 640 gauss), diffraction efficiency ～90% can be observed. To further elaborate the above result, a typical behavior of recording and erasure of hologram with respect to time has been investigated. Result manifest that GaAs:Cr is efficient, ultrafast writing and erasing media for PR-grating.