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4-ms response time in a photorefractive polymer

Efficient photorefractive polymers hold great potential for optical data processing and storage and so have been a topic of intense investigations in recent years. Materials with nearly 100 percent diffraction efficiencies have been developed, but these have been generally characterized by much slower response than their less efficient inorganic counterparts. In this report, we describe a 4-ms initial rise-time using a visible-transparent chromophore in a PVK- based polymer of Tg equals 39 degrees C for 48-V/micrometers bias projected along the grating vector and 250-mW/cm2 writing beams. This fast component consistently accounts for 90 percent of the steady-state response and is analyzed as a function of bias field. We also present transient ellipsometry measurements of an orientational response significantly faster than the grating development, suggesting that chromophores alignment sped does not limit transient grating formation. We describe the role of such underlying property measurements in understanding photorefractive transient behavior, and prospects for further improvements.