Electric-field stabilization and competition of gratings in a photorefractive polymer

Authors

• Stephen Ducharme, University of Nebraska-LincolnFollow
• Brian Jones, University of Nebraska-Lincoln
• James M. Takacs, University of Nebraska-LincolnFollow
• Lei Zhang, University of Nebraska-Lincoln

Document Type

Article

Date of this Version

1-1993

Comments

Published in OPTICS LETTERS / Vol. 18, No. 2 / January 15, 1993, pp. 152-154. Copyright © 1993 Optical Society of America. Used by permission.

Abstract

We report observations of electric-field stabilization of gratings and grating competition in a new photorefractive polymer mixture composed of 40 wt. % diethylamino-benzaldehyde-diphenyl hydrazone dissolved in Bisphenol A 4,4'-nitroaminotolane. Gratings formed with a 650-nm optical wavelength in 145-μm-thick films at 138-kV/cm bias field have a diffraction efficiency as high as 0.11%, require an energy density of –1 J/cm² for formation, and show cancellation, revelation, and electric-field-stabilized persistence. We propose a model in which fast recording is associated with one set of photosensitive traps, whereas a slower cancellation and subsequent revelation are associated with a competing grating formed in a set of insensitive shallow traps. The model also accounts for observed fatigue of the photoconductivity.