Comparison between continuous-wave and pulsed photorefraction in barium titanate

Abstract

A numerical model of photorefraction in barium titanate with simultaneous hole and electron photoconductivity and combined deep and secondary photorefractive centers is compared with experimental observations of both continuous-wave (10 mW/cm2–20 W/cm2) and pulsed high-peak-intensity (1–40 MW/cm2) laser illumination. Between 10 mW/cm2 and 20 W/cm2 (continuous wave) and below ~10 MW/cm2 (pulsed) the sample is hole dominated and has a sublinear intensity-dependent response time, whereas above ~12 MW/cm2 (pulsed) the crystal displays dominant electron conductivity and has a superlinear intensity-dependent response time.